[CI] Improve automated checks (#2702)

* same stuff, but with some more spurious error supression

* fix issue in permissions found in this

* fix a few more spurious errors

* fix another issue

* semi-spurious error fixes

* .

* formatting

* move this to properly log

* distutils import + virtualenv

* more fixes

tox.ini

@@ -11,13 +11,15 @@ envlist =
 skip_missing_interpreters = True
 
 [testenv]
-description = Run unit tests with pytest
+description = Run tests and basic automatic issue checking.
 whitelist_externals =
     pytest
+    pylint
 extras = voice, test, mongo
 commands =
     python -m compileall ./redbot/cogs
     pytest
+    pylint ./redbot
 
 [testenv:docs]
 description = Attempt to build docs with sphinx-build