Update Travis deploy for multiple networkx jobs
Update Travis deploy for multiple networkx jobs

https://github.com/dhimmel/obonet/pull/7 enabled testing for multiple versions of networkx in the Travis CI configuration. Only deploy to PyPI from a single version.

Remove branch condition as per https://docs.travis-ci.com/user/deployment#Conditional-Releases-with-on%3A

> tags: When set to true, the application is deployed when a tag is applied to the commit. This causes the branch condition to be ignored.
dhimmel/obo