Merge pull request #358 from phindmarsh/develop

Added `getQuerystringIdentifier()` to the GrantType interface
Update LICENSE
follows interface for ->decode() method
fixes #361 - only requires 'id_token' column if the 7th parameter is set
fixes EncryptionInterface typehinting in JwtBearer grant type constructor
Rename JWTBearerTest.php to JwtBearerTest.php
improves tests for JWT grant type by passing the Encryption Util in the constructor
addresses #363 - temporary fix, but this will require more thought later, as custom headers require a subclass
Merge pull request #364 from bshaffer/quick-fix-for-363

addresses #363 - temporary fix, but this will require more thought later...