Open text files in universal-newline mode.
Bugfix: temporary files were not cleaned up.
Merge branch 'master' into dev
Add `--frequency-type` to `taxit create`

* Require for PhyML AA only
* Add tests for both empirical, model frequencies
Clean up
Update phylo_model automatically in `taxit update`
switching submodule url to port 443
Merge '64-phyml-empirical-freqs' into dev
versioneer
Merge branch 'dev'
Release 0.5.2