I'm still on 4.2, but checking the release notes for 4.3 suggests it too has the problem of being dependent on psycopg2 versus psycopg2-binary. This results in the annoying message:
/usr/local/lib/python3.6/dist-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
My package also had this problem, and the fix was to replace the reference to psycopg2 with psycopg2-binary in setup.py. I hope that helps,