Introduces SAML tests which execute full response processing and
compare user attributes. tesdata now includes a full, self-signed
CA and documents signed using xmlsec1.
Adds deprication notices to existing tests, but don't remove them
since they still provide coverage.
* Improve Order of Namespace Declarations and Attributes in Canonical XML. This is related to an issue in goxmldsig for which I created an [pull request](https://github.com/russellhaering/goxmldsig/pull/17).
* Do not compress the AuthnRequest if `HTTP-POST` binding is used.
* SAML Response is valid if the Message and/or the Assertion is signed.
* Add `AssertionConsumerServiceURL` to `AuthnRequest`
* Validate Status on the Response
* Validate Conditions on the Assertion
* Validation SubjectConfirmation on the Subject
