Can't run tests that require scipy in parallel

[ketch]

We currently can't install both petsc4py and scipy on Travis; see #499. Because of this, when testing in parallel we skip any test that require scipy.

[mandli]

It looks like that was merged, do you mean it is causing this problem?

[ketch]

Yes, #499 was merged; it gives us scipy for one build and petsc4py for the other (see Aron Ahmadia's comments in the discussion there). Prior to that we had no scipy on Travis at all. This is just a reminder that this issue remains (scipy and petsc4py are mutually exclusive in our Travis builds) remains.

[mandli]

Ah, ok. Hope we can get this to work!