Add a simple test for plot_array_distribution.
Uncomment matplotlib in .travis.yml
Use Agg backend.
Try xvfb
Test using savefig.
Add a DISPLAY variable.
Remove the savefig.
Add a comment.
Add some comments to .travis.yml.
Add round_trip_counter and tests.
Make fill do 1*len(view) roundtrips.

Previously was 2*len(view) roundtrips.
Reduce the number of round trips for DistArray.from_localarrays

Now reduced to 0, 1, or 1 per engine. Depending on the arguments.
Add tests for DistArray.from_localarrays
WIP: Fix TestDnpyFileIO with remote cluster

Also refactor it a little.
WIP: Fix TestNumpyFileLoad for a remote cluster
Merge pull request #373 from cowlicks/fill-roundtrips

Make fill do 1*len(view) roundtrips.
WIP: Pull out the cleanup_file function.
Fix TestHdf5FileSave.test_save_block...

to work with a remote cluster.
Fix TestHdf5FileSave.test_save_3d...

to work with a remote cluster.

Also factor out `check_file` to a reusable `check_hdf5_file` function.
Fix TestHdf5FileSave.test_save_two_datasets...

to work with a remote cluster.