Version 5.0.1

Allow resourceLink to be null for a UserResult object
Fix bug when error occurs with call to Result service in ResourceLink->doOutcomesService
Fix tests for missing parameters with LtiSubmissionReviewRequest message
Do not enable LTI 2 platforms by default
Correct return type for Tool::findService method
Avoid creation of platform record when LTI 2 not supported by tool
Fix data type errors
Use ServiceDefinition class for ToolProxy service
Set default alg value when parsing a key with Firebase JWT client