switch from Travis to Actions for CI

[amoodie]

The objective is to transition from Travis to Github Actions as our CI.

I have set up building, testing, documentation, and releases to PyPi with #62. However, it's really hard to test that the Actions work as expected without actually doing the action that triggers the Actions. So I have made a checklist below that will track the actual validation that all components of the transition are working as expected.

• build on three operating systems and run tests
• report coverage correctly example here
• build docs as a test every PR (but do not deploy)
• only deploy docs to the website when pushed (merge) to develop
• build and deploy a release to PyPi when a "release" is created on Github

Close this issue once all the items have been verified.

[amoodie]

Actions seems great! Thanks @elbeejay for the efforts on making the docs deploy correctly. What is left is to make sure that "releases" get uploaded to pypi correctly. We should chat with @ericbarefoot and try this by making a 1.1 release at some point.

I'm going to make an effort to clean up the documentation to point to the new badges using Actions and to get rid of Travis CI files.

[amoodie]

We have successfully created a release (v1.1.2a) and it was pushed to pypi. So I'm closing this issue.

Additioanlly, I'm closing #38, which will resolve this milestone