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
Rename astropy.models to astropy.modeling
Rename astropy.modeling.builtin_models to astropy.modeling.models
Renaming astropy models to modeling in code and docs
Merge pull request #1063 from cdeil/models_restructure

Rename astropy models to modeling and builtin_models to models
refactored ndim -> n_inputs and outdim -> n_outputs
fixed typo
fixed n_inputs back to n_dim where we really wanted to have an array.
found some more outdims and changed them
changed documentation wording
fixed some of the wrongly changed ndims back