Python3 WIP

[bmoscon]

Does not current fully function. This PR is the bare minimum number of changes to

1. Ensure the package is pip-installable and installable with setup tools.
2. Removes libraries that do not support python3
3. Minimal code changes to ensure as few errors/failures as possible when running tests.

2 failure types remain:

• ImportError: Building module gryphon.execution.harness.harness failed: ['ImportError: Building module gryphon.execution.harness.exchange_coordinator failed: ["ModuleNotFoundError: No module named \'monkeypatch_timeit\'\\n"]\n']
• AttributeError: module 're' has no attribute '_pattern_type'

The latter would need to be fixed by upgrading to a newer version of sure as _pattern_type was dropped from 3.7 in favor of re.Pattern

One other concern is the removal of line_profiler which also seems to have a known issue, see rkern/line_profiler#132

My belief is that this is a good starting point for others (and myself) to continue working on python3 support

[bmoscon]

from my local testing:

261 tests run in 0.900 seconds.
7 errors (254 tests passed)

[cclauss]

Is this going to preserve Python 2 functionality? Did you try tools like futurize or modernize? The six module is a dependency so that can be used.

[bmoscon]

@cclauss no. I spoke with @garethdmm about which route he preferred and he said for now to just make python3 only changes to this branch. I'm well aware of how to support python2 and 3 in a project but did not choose to do so because python2 is EOL and most major libraries have already pledged their support for Python3 only going forward.

[bmoscon]

also, getting the tests to pass is one thing, some of the libraries the python2 version uses are extremely old and deprecated, or no longer maintained. Some are also python2 only, so even once the tests pass there are undoubtedly going to be some major changes.