Python 3 support

[kannibalox]

Depends on pyroscope/pyrobase#6

Notes:

• I didn't auto-add list() to things, it could introduce some subtle bugs but it would be much uglier
• peak.util.proxies.ProxyTypes was imported wholesale, I checked the license to make sure it was kosher but you might want to double check me on that
• auvyon didn't seem to be used anywhere and was removed to spare everyone another PR.
• 2.6 was previously allowed, this change forces either 2.7 or 3.5
• linting fatally fails midway through due to AttributeError: 'NoneType' object has no attribute 'infer' pylint-dev/pylint#1817
• update-to-head.sh is broken due to paver -q develop -U trying to install the non-py3 pyrobase

[YenForYang]

Ah unfortunate that this fails

[kannibalox]

It succeeds just fine when pyroscope/pyrobase#6 is installed

[pyroscope]

Make 'utf-8' explicit, because Python2 differs.

[Amar1729]

@kannibalox

To fix some of the current issues, I added:

• coverage to requirements-dev.txt
• git+https://github.com/kannibalox/pyrobase.git@py3 to requirements.txt (removed pyrobase>=0.5)

on my local that makes paver test and paver functest work, but installtest is still unreliable since it pretty much tries using python2.

[Amar1729]

Also, came up with a few fixes to pavement.py and update-to-head.sh that could help in getting paver installtest running properly (diff upload as a patch):

https://gist.github.com/Amar1729/9500b8878f1f90546bf32e1414534553

[kannibalox]

I appreciate the update, but most importantly though @pyroscope's source is canonical, I don't want my fork to be hardcoded anywhere.

[kannibalox]

Any word on this? It's literally the last library I use that doesn't support py3, and I'm at the point where I no longer use py2 anymore.

[pyroscope]

pyrobase first, which is almost done.

[pyroscope]

@kannibalox BTW, I decided – unlike with pyrobase – to go immediately Python 3.6+ only after the 1.0 release, which will make things a lot more streamlined in the short and long term.

Please keep this open for visibility and applying relevant parts of your work / patches.

[kannibalox]

I missed updating the metadata to reflect it, but I'm using this code on version 3.6.9. Thanks for all the work you've put in, I'll definitely keep this open.