* Define dev requirements in `requirements-dev.in`.
* Add `pip-tools` as a dev requirement.
* Remove `pip-compile` as a prerequisite for `pip-install-local`.
To avoid the bootstrapping issue in a fresh Python environment where `pip-compile` isn't installed yet.
* Update `.PHONY` config in `Makefile` to include all non-file targets.
* Update `help` target in `Makefile` to include all available commands.
* Replace tabs in `Makefile` strings with spaces.
* Update CI instructions for fixing lint errors.
Mikaël Ducharme
Sean Rose