Zuul gates broke for Spyglass due to an update made to either Zuul or
Openstack's Zuul jobs (I wasn't able to pin it down). The update caused
Zuul to attempt to install Spyglass's requirements.txt file instead of
referring to the method given in the tox configuration that utilizes
Pipenv. To bypass this issue, the requirements.txt will be removed and
Spyglass will be fully moved over to using Pipenv.
Removes requirements.txt
Updates Pipfile and Pipfile.lock for new package releases
Updates Dockerfile to install requirements from Pipfile.lock
Change-Id: I347ef6db18a44e1b88c811aa071ba8c60bccbd53
166483d6ad