More detailed error for "no such function to mock"

[MattVonVielen]

In this situation, there is already a module (somewhere) named 'test'. The error we get is this:

foo_test: bar_test_case...*failed*                                                                                                                                                                             
in function hoax_expect:assert_exported/2 (src/hoax_expect.erl, line 12)
in call from hoax:mock/2 (src/hoax.erl, line 24)
in call from foo_test:bar_test_case/0 (test/foo_test.erl, line 135)
**error:{no_such_function_to_mock,{test_api,1}}

A better error might be:

**error:{no_such_function_to_mock,"test:test_api/1", "/source/path/from/metadata/for/test.erl_or_beam"}