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

--- a/Gemfile
+++ b/Gemfile
@@ -1,18 +1,18 @@
 source 'https://rubygems.org'
 
-gem 'rails', '4.2.7.1'
-gem 'rails-deprecated_sanitizer', '~> 1.0.3'
+gem 'rails', '~> 4.2.7', '>= 4.2.7.1'
+gem 'rails-deprecated_sanitizer', '~> 1.0', '>= 1.0.3'
 
 # Responders respond_to and respond_with
 gem 'responders', '~> 2.0'
 
 # Specify a sprockets version due to increased performance
 # See https://gitlab.com/gitlab-org/gitlab-ce/issues/6069
-gem 'sprockets', '~> 3.6.0'
+gem 'sprockets', '~> 3.6'
 gem 'sprockets-es6'
 
 # Default values for AR models
-gem 'default_value_for', '~> 3.0.0'
+gem 'default_value_for', '~> 3.0'
 
 # Supported DBs
 gem 'mysql2', '~> 0.3.16', group: :mysql
@@ -20,22 +20,22 @@
 
 # Authentication libraries
 gem 'devise',                 '~> 4.0'
-gem 'doorkeeper',             '~> 4.2.0'
-gem 'omniauth',               '~> 1.3.1'
-gem 'omniauth-auth0',         '~> 1.4.1'
+gem 'doorkeeper',             '~> 4.2'
+gem 'omniauth',               '~> 1.3', '>= 1.3.1'
+gem 'omniauth-auth0',         '~> 1.4', '>= 1.4.1'
 gem 'omniauth-azure-oauth2',  '~> 0.0.6'
 gem 'omniauth-bitbucket',     '~> 0.0.2'
-gem 'omniauth-cas3',          '~> 1.1.2'
-gem 'omniauth-facebook',      '~> 3.0.0'
-gem 'omniauth-github',        '~> 1.1.1'
-gem 'omniauth-gitlab',        '~> 1.0.0'
+gem 'omniauth-cas3',          '~> 1.1', '>= 1.1.2'
+gem 'omniauth-facebook',      '>= 3.0', '< 5.0'
+gem 'omniauth-github',        '~> 1.1', '>= 1.1.1'
+gem 'omniauth-gitlab',        '~> 1.0'
 gem 'omniauth-google-oauth2', '~> 0.4.1'
 gem 'omniauth-kerberos',      '~> 0.3.0', group: :kerberos
-gem 'omniauth-saml',          '~> 1.6.0'
-gem 'omniauth-shibboleth',    '~> 1.2.0'
-gem 'omniauth-twitter',       '~> 1.2.0'
-gem 'omniauth_crowd',         '~> 2.2.0'
-gem 'rack-oauth2',            '~> 1.2.1'
+gem 'omniauth-saml',          '~> 1.6'
+gem 'omniauth-shibboleth',    '~> 1.2'
+gem 'omniauth-twitter',       '~> 1.2'
+gem 'omniauth_crowd',         '~> 2.2'
+gem 'rack-oauth2',            '~> 1.2', '>= 1.2.1'
 gem 'jwt'
 
 # Spam and anti-bot protection
@@ -43,9 +43,9 @@
 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', '~> 3.0.0'
+gem 'attr_encrypted', '~> 3.0'
 gem 'u2f', '~> 0.2.1'
 
 # Browser detection
@@ -53,12 +53,12 @@
 
 # Extracting information from a git repository
 # Provide access to Gitlab::Git library
-gem 'gitlab_git', '~> 10.4.7'
+gem 'gitlab_git', '~> 10.4', '>= 10.4.7'
 
 # 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 'omniauth-ldap', '~> 1.0.4', require: "omniauth-ldap"
+gem 'omniauth-ldap', '~> 1.0', '>= 1.0.4', require: "omniauth-ldap"
 
 # Git Wiki
 # Required manually in config/initializers/gollum.rb to control load order
@@ -66,7 +66,7 @@
 gem 'gollum-rugged_adapter', '~> 0.4.2', require: false
 
 # Language detection
-gem 'github-linguist', '~> 4.7.0', require: 'linguist'
+gem 'github-linguist', '~> 4.7', require: 'linguist'
 
 # API
 gem 'grape',        '~> 0.15.0'
@@ -77,7 +77,7 @@
 gem 'kaminari', '~> 0.17.0'
 
 # HAML
-gem 'hamlit', '~> 2.6.1'
+gem 'hamlit', '~> 2.6', '>= 2.6.1'
 
 # Files attachments
 gem 'carrierwave', '~> 0.10.0'
@@ -101,79 +101,79 @@
 gem 'six', '~> 0.2.0'
 
 # Seed data
-gem 'seed-fu', '~> 2.3.5'
+gem 'seed-fu', '~> 2.3', '>= 2.3.5'
 
 # Markdown and HTML processing
-gem 'html-pipeline', '~> 1.11.0'
-gem 'task_list',     '~> 1.0.2', require: 'task_list/railtie'
+gem 'html-pipeline', '~> 1.11'
+gem 'task_list',     '~> 1.0', '>= 1.0.2', require: 'task_list/railtie'
 gem 'github-markup', '~> 1.4'
-gem 'redcarpet',     '~> 3.3.3'
-gem 'RedCloth',      '~> 4.3.2'
+gem 'redcarpet',     '~> 3.3', '>= 3.3.3'
+gem 'RedCloth',      '~> 4.3', '>= 4.3.1'
 gem 'rdoc',          '~> 4.1'
 gem 'org-ruby',      '~> 0.9.12'
 gem 'creole',        '~> 0.5.0'
 gem 'wikicloth',     '0.8.1'
-gem 'asciidoctor',   '~> 1.5.2'
+gem 'asciidoctor',   '~> 1.5', '>= 1.5.2'
 gem 'rouge',         '~> 2.0'
 
 # See https://groups.google.com/forum/#!topic/ruby-security-ann/aSbgDiwb24s
 # and https://groups.google.com/forum/#!topic/ruby-security-ann/Dy7YiKb_pMM
-gem 'nokogiri', '~> 1.6.7', '>= 1.6.7.2'
+gem 'nokogiri', '~> 1.6', '>= 1.6.7.2'
 
 # Diffs
-gem 'diffy', '~> 3.0.3'
+gem 'diffy', '~> 3.0', '>= 3.0.3'
 
 # Application server
 group :unicorn do
-  gem 'unicorn', '~> 4.9.0'
+  gem 'unicorn', '>= 4.9'
   gem 'unicorn-worker-killer', '~> 0.4.2'
 end
 
 # State machine
 gem 'state_machines-activerecord', '~> 0.4.0'
 # Run events after state machine commits
-gem 'after_commit_queue', '~> 1.3.0'
+gem 'after_commit_queue', '~> 1.3'
 
 # Issue tags
 gem 'acts-as-taggable-on', '~> 3.4'
 
 # Background jobs
-gem 'sinatra', '~> 1.4.4', require: false
+gem 'sinatra', '~> 1.4', '>= 1.4.4', require: false
 gem 'sidekiq', '~> 4.0'
 gem 'sidekiq-cron', '~> 0.4.0'
-gem 'redis-namespace', '~> 1.5.2'
+gem 'redis-namespace', '~> 1.5', '>= 1.5.2'
 
 # HTTP requests
 gem 'httparty', '~> 0.13.3'
 
 # Colored output to console
-gem 'rainbow', '~> 2.1.0'
+gem 'rainbow', '~> 2.1'
 
 # GitLab settings
-gem 'settingslogic', '~> 2.0.9'
+gem 'settingslogic', '~> 2.0', '>= 2.0.9'
 
 # Misc
 
-gem 'version_sorter', '~> 2.1.0'
+gem 'version_sorter', '~> 2.1'
 
 # Cache
-gem 'redis-rails', '~> 4.0.0'
+gem 'redis-rails', '~> 4.0'
 
 # Redis
 gem 'redis', '~> 3.2'
 gem 'connection_pool', '~> 2.0'
 
 # HipChat integration
-gem 'hipchat', '~> 1.5.0'
+gem 'hipchat', '~> 1.5'
 
 # Flowdock integration
-gem 'gitlab-flowdock-git-hook', '~> 1.0.1'
+gem 'gitlab-flowdock-git-hook', '~> 1.0', '>= 1.0.1'
 
 # Gemnasium integration
 gem 'gemnasium-gitlab-service', '~> 0.2'
 
 # Slack integration
-gem 'slack-notifier', '~> 1.2.0'
+gem 'slack-notifier', '~> 1.2'
 
 # Asana integration
 gem 'asana', '~> 0.4.0'
@@ -182,29 +182,29 @@
 gem 'ruby-fogbugz', '~> 0.2.1'
 
 # d3
-gem 'd3_rails', '~> 3.5.0'
+gem 'd3_rails', '~> 3.5'
 
 # underscore-rails
-gem 'underscore-rails', '~> 1.8.0'
+gem 'underscore-rails', '~> 1.8'
 
 # Sanitize user input
 gem 'sanitize', '~> 2.0'
-gem 'babosa', '~> 1.0.2'
+gem 'babosa', '~> 1.0', '>= 1.0.2'
 
 # Sanitizes SVG input
-gem 'loofah', '~> 2.0.3'
+gem 'loofah', '~> 2.0', '>= 2.0.3'
 
 # Working with license
-gem 'licensee', '~> 8.0.0'
+gem 'licensee', '~> 8.0'
 
 # Protect against bruteforcing
-gem 'rack-attack', '~> 4.3.1'
+gem 'rack-attack', '~> 4.3', '>= 4.3.1'
 
 # Ace editor
-gem 'ace-rails-ap', '~> 4.1.0'
+gem 'ace-rails-ap', '~> 4.1'
 
 # Keyboard shortcuts
-gem 'mousetrap-rails', '~> 1.4.6'
+gem 'mousetrap-rails', '~> 1.4', '>= 1.4.6'
 
 # Detect and convert string character encoding
 gem 'charlock_holmes', '~> 0.7.3'
@@ -213,30 +213,30 @@
 gem 'chronic', '~> 0.10.2'
 gem 'chronic_duration', '~> 0.10.6'
 
-gem 'sass-rails', '~> 5.0.0'
-gem 'coffee-rails', '~> 4.1.0'
-gem 'uglifier', '~> 2.7.2'
-gem 'turbolinks', '~> 2.5.0'
-gem 'jquery-turbolinks', '~> 2.1.0'
-
-gem 'addressable',        '~> 2.3.8'
-gem 'bootstrap-sass',     '~> 3.3.0'
-gem 'font-awesome-rails', '~> 4.6.1'
+gem 'sass-rails', '~> 5.0'
+gem 'coffee-rails', '~> 4.1'
+gem 'uglifier', '~> 2.7', '>= 2.7.2'
+gem 'turbolinks', '~> 2.5'
+gem 'jquery-turbolinks', '~> 2.1'
+
+gem 'addressable',        '~> 2.3', '>= 2.3.8'
+gem 'bootstrap-sass',     '~> 3.3'
+gem 'font-awesome-rails', '~> 4.6', '>= 4.6.1'
 gem 'gemojione',          '~> 3.0'
-gem 'gon',                '~> 6.1.0'
-gem 'jquery-atwho-rails', '~> 1.3.2'
-gem 'jquery-rails',       '~> 4.1.0'
-gem 'jquery-ui-rails',    '~> 5.0.0'
-gem 'request_store',      '~> 1.3.0'
-gem 'select2-rails',      '~> 3.5.9'
-gem 'virtus',             '~> 1.0.1'
-gem 'net-ssh',            '~> 3.0.1'
+gem 'gon',                '~> 6.1'
+gem 'jquery-atwho-rails', '~> 1.3', '>= 1.3.2'
+gem 'jquery-rails',       '~> 4.0'
+gem 'jquery-ui-rails',    '~> 5.0'
+gem 'request_store',      '~> 1.3'
+gem 'select2-rails',      '~> 3.5', '>= 3.5.9'
+gem 'virtus',             '~> 1.0', '>= 1.0.1'
+gem 'net-ssh',            '~> 3.0', '>= 3.0.1'
 gem 'base32',             '~> 0.3.0'
 
 # Sentry integration
-gem 'sentry-raven', '~> 1.1.0'
+gem 'sentry-raven', '~> 1.1'
 
-gem 'premailer-rails', '~> 1.9.0'
+gem 'premailer-rails', '~> 1.9'
 
 # Metrics
 group :metrics do
@@ -327,7 +327,7 @@
 
 gem 'newrelic_rpm', '~> 3.16'
 
-gem 'octokit', '~> 4.3.0'
+gem 'octokit', '~> 4.3'
 
 gem 'mail_room', '~> 0.8'
 
@@ -336,18 +336,18 @@
 gem 'ruby-prof', '~> 0.15.9'
 
 ## CI
-gem 'activerecord-session_store', '~> 1.0.0'
+gem 'activerecord-session_store', '~> 1.0'
 gem 'nested_form', '~> 0.3.2'
 
 # OAuth
-gem 'oauth2', '~> 1.2.0'
+gem 'oauth2', '~> 1.2'
 
 # Soft deletion
 gem 'paranoia', '~> 2.0'
 
 # Health check
-gem 'health_check', '~> 2.1.0'
+gem 'health_check', '~> 2.1'
 
 # System information
 gem 'vmstat', '~> 2.2'
-gem 'sys-filesystem', '~> 1.1.6'
+gem 'sys-filesystem', '~> 1.1', '>= 1.1.6'