Requirements are too strict with pip 20.3

[sodul]

We install the docker package alongside other ones that have similar dependencies. Unfortunately the requirement.txt entries for the docker package are strict and conflicting with other projects such as hvac.
https://pip.pypa.io/en/latest/user_guide/#fixing-conflicting-dependencies

The required versions need to be relaxed in order to be installable with pip 20.3

[milas]

The upcoming release has relaxed restrictions and removed many extraneous transitive dependencies. Once 6.0.0 is out, please open a new issue if you have trouble with the latest pip.