show mock failures for commands

[arlimus]

Does 2 things:

1 Use the :verbose option to show when commands and file mocks fail:

Command not mocked:
    powershell -encodedCommand JAB...KAA==
    SHA: b00eb49a98c96a808c469e4894b5123a913e354c9ffea5b785898fe30d288ee0

2 Change the old :verbose to :trace and fixed that whole section of code. You now get access to tracing again with e.g.

Train.create(:mock, { trace: true })

[arlimus]

This will force a minor version upgrade ;)

[chris-rock]

this is a lifesaver improvement @arlimus