Uses 'kazoo-2.5.0' branch name for installing SolrClient instead of
the commit hash and adds flake8 as a dev package. This means that I
can track dependencies for production and development and still end
up with a requirements.txt for produciton.
Eventually I'd like to be able to use pipenv instead of plain pip.
For now I'll just keep using pipenv and generating requirements.txt
like this:
$ pipenv run pip freeze > requirements.txt
Then I can kinda have the best of both worlds, where I use pipenv
on my local machine and pip with requirements.txt on the server.