WIP ENH: Quieter Travis

Not ready for merge or review. Should just make the Travis logs easier to parse by omitting things we don't care about (like the `pip` logs). This will make it slightly harder to debug Travis *testing platform* issues, but easier to debug real Travis *mne-python testing* errors.
I commented these lines because a) they were outdated (`fiff` in the paths) and b) even with them corrected to use `io` I still got red text saying that there were no previously included files being excluded. @agramfort do we need these lines?