Removing the moto.

This is step 3 of DE-1824.

Also update:
* six 1.13.0 => 1.14.0
* edx-django-utils 2.0.2 => 2.0.3
* skip test that checks all model changes have migrations.  (We defer
  this to step 4.)

Bump django-filter.
Rename the name to field-name.

* Added pytest-json-report plugin
	- modifying app-opts in setup.cfg
	- adding hook to all conftest.py files in repo
	- setting report to be saved to test_root/log/warnings.json
	- Writing custom logic to save json report to avoid overwrite if pytest called twice
This was created to allow us to easily parse through test warnings in jenkins

* Switch make upgrade to Python 3.5

* bok-choy fixes, constrain django-debug-toolbar

* Remove flaky bok-choy test

DE-1824: step 2 of 4 in renaming 'exists' field in ThirdPartyTranscriptCredentialsState to 'has_creds' (v1.1.33)

The coverage version shouldn't matter, but why not use the latest?

The plugin version fixes an encoding issue.

Bump the version.

Some change in the requirements here may be responsible for increased
CPU and memory usage.  This is causing production LMS for edx.org to run
into lots of performance issues.  Reverting for now until we can narrow
it down to which change caused the issue.

Bumping edx-organizations will add history to the Organization model.

DE-1510

Extra constraints needed to be added for pytest-randomly and tornado,
both of which have dropped Python 2 support.