Merge branch 'release/v1.0.0' into develop

* release/v1.0.0:
  Adding VERSION constant to SingleSignOn
  Adding LICENSE.txt
Adding Secret class
Refactoring QuerySigner to use Secret
Replacing QuerySigner with a Secret object and SingleSignOn::validates() static method
Merge branch 'feature/secret' into develop

* feature/secret:
  Replacing QuerySigner with a Secret object and SingleSignOn::validates() static method
  Refactoring QuerySigner to use Secret
  Adding Secret class
Refactoring QueryString logic into separate class
Bumping version to 1.2.0
Merge branch 'release/v1.2.0'

* release/v1.2.0:
  Bumping version to 1.2.0
  Refactoring QueryString logic into separate class
  Replacing QuerySigner with a Secret object and SingleSignOn::validates() static method
  Refactoring QuerySigner to use Secret
  Adding Secret class