v1.7.4: Updates to deal with cert issues, docker improvements, and python3 improvements

This release incorporates some changes to make python3 work better. It also adds some nuance with Docker, so that both ubuntu and centos versions of the package can now be built in Docker. It also removes the bundled certs, so that people who install the package can no longer run into trouble by relying on our certs when they expire.

v1.7.2

Includes a fix Python 2 minimum version checks.

v1.7.1

Fixes related to Python 3 support.