Isort: Automatic deployment to pypi

[jasongi-actu]

I think it would be a good idea to build into Travis-CI deploying to pypi. This would prevent issues like #760 from occurring.

The guide looks fairly simple and would require @timothycrosley to encrypt the pypi credentials in the config file.
https://docs.travis-ci.com/user/deployment/pypi/

[hugovk]

Here's an example (https://github.com/pylast/pylast/pull/295):

https://github.com/pylast/pylast/blob/a5c53dbf5402535ca79c66cebe1ca1e1a3dc7baa/.travis.yml#L47-L70

It has two deploys:

• tagged commits deploy to the main pypi.org
• untagged commits deploy to test.pypi.org

For both, it only does it for builds to the pylast/pylast main repo (no forks), on the master branch (no feature branches), and for a single build job (py37, no duplicates).

[timothycrosley]

Thanks for the assistance! Using these pages as guides, isort now has auto deploy setup.

Thanks!

~Timothy