We have a handful of dependencies that are actually dependencies of

other dependencies. To avoid installation issues on Python 2.7 systems,

where some of our dependencies ended up installing Python 3-only

packages, we began to pin some dependencies-of-dependencies in our

setup.py. When doing so, we also specified some minimum versions for

Python 3.
This actually made the Python 3 situation more complex, since we were

now fighting some of the version specifiers in some dependencies.

Namely, bcrypt and pyparsing. Really, we only wanted to pin on

Python 2.7 anyway.
These pinned dependencies have been updated to only pin on Python 2.7.

For Python 3, we now stay out of the picture, allowing our dependencies

to specify the versions of their dependencies that they want.

Built packages and verified that the version specifiers for bcrypt

and pyparsing were only set for Python 2.7.
Verified that this avoided some installation issues.