Improve run.py so this works nicely on Travis-ci.

Essentially set an exit status to notify of success/failure with
slightly better reporting on each test.
BUG: Create log dir if it doesn't exist.

This happens when the tests are run for the first time without ever
starting mayavi.
BUG: animate decorator was not returning animator.

This makes it hard to control the animator.  Also added show/close
methods to the animator to show/close the animator UI.
TEST: Many fixes to mlab integration tests.

Improves a few issues:

 1. All mlab test* functions are run nicely and animations are shown,
    the animation UI is closed automatically. The code is cleaned up and
    reused.
 2. Changes so the tests can run without user intervention.
Merge branch 'master' into run_integration_tests
Try to run integration tests on travis-ci.
BUG: Stop event loop after test completes.
Merge pull request #108 from prabhuramachandran/run_integration_tests

Run integration tests