Merge pull request #1 from kivra/master

Documentation about testing updated
New issue_code_grant/3 and issue_code_grant/4
Commented warnings_as_errors out to fix issue #8.
Merge branch 'master' into New_issue_code_grant_functions
Added functions to issue code grant without verifying the client
Merge pull request #10 from IvanMartinez/master

Added issue_code_grant/3 and issue_code_grant/4