corrected test message
replaced throw_error with throw_exception
wrote tests for NoParentGivenToSubtype
Wrote exception class NoParentGivenToSubtype
replaced throw_error with throw_exception
added tests for EnumCalledWithAnArrayRefAndAdditionalArgs
Wrote exception class EnumCalledWithAnArrayRefAndAdditionalArgs
replaced throw_error with throw_exception
wrote tests for UnionCalledWithAnArrayRefAndAdditionalArgs
wrote exception class UnionCalledWithAnArrayRefAndAdditionalArgs