Added unit tests to Github Actions (#16610)

* Added unit tests to Github Actions

* Set user e-mail and name for git tests to succeed

* Simplify setup.sh logic

* Replicate Travis script on Github Actions

* Update flags since '.' is not allowed

* Added badge, simplified workflow

* Remove pinning of coverage

* Remove unit tests run on Github Actions from Travis

README.md

@@ -1,9 +1,10 @@
 # <img src="https://cdn.rawgit.com/spack/spack/develop/share/spack/logo/spack-logo.svg" width="64" valign="middle" alt="Spack"/> Spack
 
-[![](https://github.com/spack/spack/workflows/macos%20tests/badge.svg)](https://github.com/spack/spack/actions)
-[![Build Status](https://travis-ci.com/spack/spack.svg?branch=develop)](https://travis-ci.com/spack/spack)
+[![MacOS Tests](https://github.com/spack/spack/workflows/macos%20tests/badge.svg)](https://github.com/spack/spack/actions)
+[![Linux Tests](https://github.com/spack/spack/workflows/linux%20tests/badge.svg)](https://github.com/spack/spack/actions)
 [![Linux Builds](https://github.com/spack/spack/workflows/linux%20builds/badge.svg)](https://github.com/spack/spack/actions)
 [![macOS Builds (nightly)](https://github.com/spack/spack/workflows/macOS%20builds%20nightly/badge.svg?branch=develop)](https://github.com/spack/spack/actions?query=workflow%3A%22macOS+builds+nightly%22)
+[![Build Status](https://travis-ci.com/spack/spack.svg?branch=develop)](https://travis-ci.com/spack/spack)
 [![codecov](https://codecov.io/gh/spack/spack/branch/develop/graph/badge.svg)](https://codecov.io/gh/spack/spack)
 [![Read the Docs](https://readthedocs.org/projects/spack/badge/?version=latest)](https://spack.readthedocs.io)
 [![Slack](https://spackpm.herokuapp.com/badge.svg)](https://spackpm.herokuapp.com)