Remove Framework Tests from saml2Login Sample

[jzheaux]

Most of the tests in the saml2Login sample are related to testing the framework.

Since the purpose of the sample is to demonstrate how Spring Security's SAML 2.0 support works, we can safely remove these tests and simplify the sample overall. We already have tests in the spring-security-saml2-service-provider and spring-security-config modules that test the framework.