* More robust algorithm to find correct executable
* Revise message wording
* Add clang-tidy and clang-format to requirements.txt.
Add to message explaining install process.
* Extracted get_binary to helpers.py. Use execptions for clean exit.
* Add parameter types
* clang-{tidy,format} in requirements_test.txt
clean up script exit
* Kill processes on ^C
* Move clang-tidy and clang-format into requirements_dev.txt
