#32 Tests for goalDefinition() function

Add tests for reading a goal annotated function / attribute and transform it into a Goal.
Those tests cover:
 - valid goals functions declarations
 - invalid goals functions declarations
 - invalid goals attributes declarations
 - noop goals declarations
 - internal goals
 - goals with specified names

Other tests needs to be added for this function:
 - inheritance of goal annotation for goal annotated methods (name, dependencies, ...)
 - internal goals methods