* reduce the number of jobs on travis
* update usage of pip due to changes in Homebrew
* update pip and ensure the right one is being used with an alias
* force reinstall pip to get `pip` on PATH
* use python2 explicitly to run catkin_make
* force use of python2 executable by catkin packages
* python!
* simpler
* how to which
* Update .travis.yml
* make tests and run_tests
* test results
* disable timer tests on macOS
