* tests: use stages for the travis execution
Fixes #694
* add comments as suggested by @nventuro
* move the unit tests first, as suggested by @frangio
* make stages clearer as suggested by @nventuro
* tests: use stages for the travis execution
Fixes #694
* add comments as suggested by @nventuro
* move the unit tests first, as suggested by @frangio
* make stages clearer as suggested by @nventuro
* update the stage names as suggested by @frangio
* Run all tests in parallel
* added names
