Expose parallel testing support at the command line
Remove the global state from the table tests so that they can be run in parallel
Merge the test_timer tests into one function since they must be run sequentially to succeed.
Fix a missed test
Fix a sometime race condition in the tests whereby `FOOBAR` would be a registered unit and therefore would not work as expected when setting to a `wcsprm.cunit` list.
Try to solve the unit definition problem
Add a custom version of catch_warnings that clears all warning state first so that we can reproducibly get all warnings everytime.
Turn on parallel testing on Travis
Install pytest-xdist on Travis
Disable parallel testing for Python 3.3