Add testing for mismatch cases

This should help catch any errors in our handling of invalid cases.
While some of these produce outputs which aren't correct, what
we're checking here is that we don't _error_ while producing that
output.

Also fix a case which this showed up.

jedi/inference/gradual/annotation.py

@@ -494,6 +494,11 @@ def _infer_type_vars(annotation_value, value_set, is_class_value=False):
             # the elements from the set first, then handle them, even if we put
             # them back in a set afterwards.
             for element in value_set:
+                if element.api_type == u'function':
+                    # Functions & methods don't have an MRO and we're not
+                    # expecting a Callable (those are handled separately above).
+                    continue
+
                 if element.is_instance():
                     py_class = element.get_annotated_class_object()
                 else: