We should be able to update minor versions of stable libs without breaking
gitlab Gemfile

--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@
 
 gem_versions = {}
 gem_versions['activerecord_sane_schema_dumper'] = rails5? ? '1.0'      : '0.2'
-gem_versions['default_value_for']               = rails5? ? '~> 3.0.5' : '~> 3.0.0'
+gem_versions['default_value_for']               = rails5? ? '~> 3.0.5' : '~> 3.0'
 gem_versions['rails']                           = rails5? ? '5.0.7'    : '4.2.10'
 gem_versions['rails-i18n']                      = rails5? ? '~> 5.1'   : '~> 4.0.9'
 # --- The end of special code for migrating to Rails 5.0 ---
@@ -13,12 +13,12 @@
 source 'https://rubygems.org'
 
 gem 'rails', gem_versions['rails']
-gem 'rails-deprecated_sanitizer', '~> 1.0.3'
+gem 'rails-deprecated_sanitizer', '~> 1.0', '>= 1.0.3'
 
 # Responders respond_to and respond_with
 gem 'responders', '~> 2.0'
 
-gem 'sprockets', '~> 3.7.0'
+gem 'sprockets', '~> 3.7'
 
 # Default values for AR models
 gem 'default_value_for', gem_versions['default_value_for']
@@ -37,35 +37,35 @@
 gem 'doorkeeper', '~> 4.3'
 gem 'doorkeeper-openid_connect', '~> 1.5'
 gem 'omniauth', '~> 1.8'
-gem 'omniauth-auth0', '~> 2.0.0'
+gem 'omniauth-auth0', '~> 2.0'
 gem 'omniauth-azure-oauth2', '~> 0.0.9'
-gem 'omniauth-cas3', '~> 1.1.4'
-gem 'omniauth-facebook', '~> 4.0.0'
+gem 'omniauth-cas3', '~> 1.1', '>= 1.1.4'
+gem 'omniauth-facebook', '~> 4.0'
 gem 'omniauth-github', '~> 1.3'
-gem 'omniauth-gitlab', '~> 1.0.2'
+gem 'omniauth-gitlab', '~> 1.0', '>= 1.0.2'
 gem 'omniauth-google-oauth2', '~> 0.5.3'
 gem 'omniauth-kerberos', '~> 0.3.0', group: :kerberos
 gem 'omniauth-oauth2-generic', '~> 0.2.2'
 gem 'omniauth-saml', '~> 1.10'
-gem 'omniauth-shibboleth', '~> 1.3.0'
+gem 'omniauth-shibboleth', '~> 1.3'
 gem 'omniauth-twitter', '~> 1.4'
-gem 'omniauth_crowd', '~> 2.2.0'
+gem 'omniauth_crowd', '~> 2.2'
 gem 'omniauth-authentiq', '~> 0.3.3'
-gem 'rack-oauth2', '~> 1.2.1'
-gem 'jwt', '~> 1.5.6'
+gem 'rack-oauth2', '~> 1.2', '>= 1.2.1'
+gem 'jwt', '~> 1.5', '>= 1.5.6'
 
 # Spam and anti-bot protection
 gem 'recaptcha', '~> 3.0', require: 'recaptcha/rails'
 gem 'akismet', '~> 2.0'
 
 # Two-factor authentication
-gem 'devise-two-factor', '~> 3.0.0'
+gem 'devise-two-factor', '~> 3.0'
 gem 'rqrcode-rails3', '~> 0.1.7'
-gem 'attr_encrypted', '~> 3.1.0'
+gem 'attr_encrypted', '~> 3.1'
 gem 'u2f', '~> 0.2.1'
 
 # GitLab Pages
-gem 'validates_hostname', '~> 1.0.6'
+gem 'validates_hostname', '~> 1.0', '>= 1.0.6'
 
 # Browser detection
 gem 'browser', '~> 2.5'
@@ -76,17 +76,17 @@
 # LDAP Auth
 # GitLab fork with several improvements to original library. For full list of changes
 # see https://github.com/intridea/omniauth-ldap/compare/master...gitlabhq:master
-gem 'gitlab_omniauth-ldap', '~> 2.0.4', require: 'omniauth-ldap'
+gem 'gitlab_omniauth-ldap', '~> 2.0', '>= 2.0.4', require: 'omniauth-ldap'
 gem 'net-ldap'
 
 # API
 gem 'grape', '~> 1.1'
 gem 'grape-entity', '~> 0.7.1'
-gem 'rack-cors', '~> 1.0.0', require: 'rack/cors'
+gem 'rack-cors', '~> 1.0', require: 'rack/cors'
 
 # GraphQL API
-gem 'graphql', '~> 1.8.0'
-gem 'graphiql-rails', '~> 1.4.10'
+gem 'graphql', '~> 1.8'
+gem 'graphiql-rails', '~> 1.4', '>= 1.4.10'
 
 # Disable strong_params so that Mash does not respond to :permitted?
 gem 'hashie-forbidden_attributes'
@@ -95,7 +95,7 @@
 gem 'kaminari', '~> 1.0'
 
 # HAML
-gem 'hamlit', '~> 2.8.8'
+gem 'hamlit', '~> 2.8', '>= 2.8.8'
 
 # Files attachments
 # Locked until https://github.com/carrierwaveuploader/carrierwave/pull/2332/files is merged.
@@ -104,9 +104,9 @@
 gem 'mini_magick'
 
 # for backups
-gem 'fog-aws', '~> 2.0.1'
+gem 'fog-aws', '~> 2.0', '>= 2.0.1'
 gem 'fog-core', '~> 1.44'
-gem 'fog-google', '~> 1.7.1'
+gem 'fog-google', '~> 1.7', '>= 1.7.1'
 gem 'fog-local', '~> 0.3'
 gem 'fog-openstack', '~> 0.1'
 gem 'fog-rackspace', '~> 0.1.1'
@@ -119,37 +119,37 @@
 gem 'unf', '~> 0.1.4'
 
 # Seed data
-gem 'seed-fu', '~> 2.3.7'
+gem 'seed-fu', '~> 2.3', '>= 2.3.7'
 
 # Markdown and HTML processing
 gem 'html-pipeline', '~> 2.8'
-gem 'deckar01-task_list', '2.0.0'
+gem 'deckar01-task_list', '2.0'
 gem 'gitlab-markup', '~> 1.6.4'
-gem 'github-markup', '~> 1.7.0', require: 'github/markup'
+gem 'github-markup', '~> 1.7', require: 'github/markup'
 gem 'redcarpet', '~> 3.4'
 gem 'commonmarker', '~> 0.17'
-gem 'RedCloth', '~> 4.3.2'
+gem 'RedCloth', '~> 4.3', '>= 4.3.2'
 gem 'rdoc', '~> 6.0'
 gem 'org-ruby', '~> 0.9.12'
 gem 'creole', '~> 0.5.0'
 gem 'wikicloth', '0.8.1'
-gem 'asciidoctor', '~> 1.5.6'
-gem 'asciidoctor-plantuml', '0.0.8'
+gem 'asciidoctor', '~> 1.5', '>= 1.5.6'
+gem 'asciidoctor-plantuml', '~> 0.0.8'
 gem 'rouge', '~> 3.1'
 gem 'truncato', '~> 0.7.9'
-gem 'bootstrap_form', '~> 2.7.0'
-gem 'nokogiri', '~> 1.8.2'
+gem 'bootstrap_form', '~> 2.7'
+gem 'nokogiri', '~> 1.8', '>= 1.8.2'
 gem 'escape_utils', '~> 1.1'
 
 # Calendar rendering
 gem 'icalendar'
 
 # Diffs
-gem 'diffy', '~> 3.1.0'
+gem 'diffy', '~> 3.1'
 
 # Application server
 group :unicorn do
-  gem 'unicorn', '~> 5.1.0'
+  gem 'unicorn', '~> 5.1'
   gem 'unicorn-worker-killer', '~> 0.4.4'
 end
 
@@ -165,9 +165,9 @@
 gem 'acts-as-taggable-on', '~> 5.0'
 
 # Background jobs
-gem 'sidekiq', '~> 5.2.1'
+gem 'sidekiq', '~> 5.2','>= 5.2.1'
 gem 'sidekiq-cron', '~> 0.6.0'
-gem 'redis-namespace', '~> 1.6.0'
+gem 'redis-namespace', '~> 1.6'
 
 # Cron Parser
 gem 'rufus-scheduler', '~> 3.4'
@@ -182,14 +182,14 @@
 gem 'ruby-progressbar'
 
 # GitLab settings
-gem 'settingslogic', '~> 2.0.9'
+gem 'settingslogic', '~> 2.0', '>= 2.0.9'
 
 # Linear-time regex library for untrusted regular expressions
-gem 're2', '~> 1.1.1'
+gem 're2', '~> 1.1', '>= 1.1.1'
 
 # Misc
 
-gem 'version_sorter', '~> 2.1.0'
+gem 'version_sorter', '~> 2.1'
 
 # Export Ruby Regex to Javascript
 gem 'js_regex', '~> 2.2.1'
@@ -198,14 +198,14 @@
 gem 'device_detector'
 
 # Cache
-gem 'redis-rails', '~> 5.0.2'
+gem 'redis-rails', '~> 5.0', '>= 5.0.2'
 
 # Redis
 gem 'redis', '~> 3.2'
 gem 'connection_pool', '~> 2.0'
 
 # HipChat integration
-gem 'hipchat', '~> 1.5.0'
+gem 'hipchat', '~> 1.5'
 
 # JIRA integration
 gem 'jira-ruby', '~> 1.4'
@@ -214,7 +214,7 @@
 gem 'flowdock', '~> 0.7'
 
 # Slack integration
-gem 'slack-notifier', '~> 1.5.1'
+gem 'slack-notifier', '~> 1.5', '>= 1.5.1'
 
 # Hangouts Chat integration
 gem 'hangouts-chat', '~> 0.0.5'
@@ -226,11 +226,11 @@
 gem 'ruby-fogbugz', '~> 0.2.1'
 
 # Kubernetes integration
-gem 'kubeclient', '~> 3.1.0'
+gem 'kubeclient', '~> 3.1'
 
 # Sanitize user input
 gem 'sanitize', '~> 4.6'
-gem 'babosa', '~> 1.0.2'
+gem 'babosa', '~> 1.0', '>= 1.0.2'
 
 # Sanitizes SVG input
 gem 'loofah', '~> 2.2'
@@ -239,10 +239,10 @@
 gem 'licensee', '~> 8.9'
 
 # Protect against bruteforcing
-gem 'rack-attack', '~> 4.4.1'
+gem 'rack-attack', '~> 4.4', '>= 4.4.1'
 
 # Ace editor
-gem 'ace-rails-ap', '~> 4.1.0'
+gem 'ace-rails-ap', '~> 4.1'
 
 # Detect and convert string character encoding
 gem 'charlock_holmes', '~> 0.7.5'
@@ -257,40 +257,40 @@
 gem 'webpack-rails', '~> 0.9.10'
 gem 'rack-proxy', '~> 0.6.0'
 
-gem 'sass-rails', '~> 5.0.6'
-gem 'uglifier', '~> 2.7.2'
+gem 'sass-rails', '~> 5.0', '>= 5.0.6'
+gem 'uglifier', '~> 2.7', '>= 2.7.2'
 
-gem 'addressable', '~> 2.5.2'
+gem 'addressable', '~> 2.5', '>= 2.5.2'
 gem 'font-awesome-rails', '~> 4.7'
 gem 'gemojione', '~> 3.3'
 gem 'gon', '~> 6.2'
-gem 'jquery-atwho-rails', '~> 1.3.2'
+gem 'jquery-atwho-rails', '~> 1.3', '>= 1.3.2'
 gem 'request_store', '~> 1.3'
-gem 'select2-rails', '~> 3.5.9'
-gem 'virtus', '~> 1.0.1'
+gem 'select2-rails', '~> 3.5', '>= 3.5.9'
+gem 'virtus', '~> 1.0', '>= 1.0.1'
 gem 'base32', '~> 0.3.0'
 
 # Sentry integration
 gem 'sentry-raven', '~> 2.7'
 
-gem 'premailer-rails', '~> 1.9.7'
+gem 'premailer-rails', '~> 1.9', '>= 1.9.7'
 
 # I18n
 gem 'ruby_parser', '~> 3.8', require: false
 gem 'rails-i18n', gem_versions['rails-i18n']
-gem 'gettext_i18n_rails', '~> 1.8.0'
+gem 'gettext_i18n_rails', '~> 1.8'
 gem 'gettext_i18n_rails_js', '~> 1.3'
 gem 'gettext', '~> 3.2.2', require: false, group: :development
 
-gem 'batch-loader', '~> 1.2.1'
+gem 'batch-loader', '~> 1.2', '>= 1.2.1'
 
 # Perf bar
-gem 'peek', '~> 1.0.1'
+gem 'peek', '~> 1.0', '>= 1.0.1'
 gem 'peek-gc', '~> 0.0.2'
-gem 'peek-mysql2', '~> 1.1.0', group: :mysql
-gem 'peek-pg', '~> 1.3.0', group: :postgres
+gem 'peek-mysql2', '~> 1.1', group: :mysql
+gem 'peek-pg', '~> 1.3', group: :postgres
 gem 'peek-rblineprof', '~> 0.2.0'
-gem 'peek-redis', '~> 1.2.0'
+gem 'peek-redis', '~> 1.2'
 gem 'gitlab-sidekiq-fetcher', require: 'sidekiq-reliable-fetch'
 
 # Metrics
@@ -399,15 +399,15 @@
 gem 'oauth2', '~> 1.4'
 
 # Health check
-gem 'health_check', '~> 2.6.0'
+gem 'health_check', '~> 2.6'
 
 # System information
-gem 'vmstat', '~> 2.3.0'
-gem 'sys-filesystem', '~> 1.1.6'
+gem 'vmstat', '~> 2.3'
+gem 'sys-filesystem', '~> 1.1', '>= 1.1.6'
 
 # SSH host key support
 gem 'net-ssh', '~> 5.0'
-gem 'sshkey', '~> 1.9.0'
+gem 'sshkey', '~> 1.9'
 
 # Required for ED25519 SSH host key support
 group :ed25519 do
@@ -416,12 +416,12 @@
 end
 
 # Gitaly GRPC client
-gem 'gitaly-proto', '~> 0.123.0', require: 'gitaly'
-gem 'grpc', '~> 1.15.0'
+gem 'gitaly-proto', '~> 0.123', require: 'gitaly'
+gem 'grpc', '~> 1.15'
 
 gem 'google-protobuf', '~> 3.6'
 
-gem 'toml-rb', '~> 1.0.0', require: false
+gem 'toml-rb', '~> 1.0', require: false
 
 # Feature toggles
 gem 'flipper', '~> 0.13.0'