Consolidate CI tools into setup.cfg and drop tox

src/setup.cfg

@@ -1,8 +1,15 @@
-[pytest]
+[pycodestyle]
+exclude = migrations, paperless/settings.py
+
+
+[tool:pytest]
 DJANGO_SETTINGS_MODULE=paperless.settings
-addopts = --pythonwarnings=all
+addopts = --pythonwarnings=all -n auto
 env =
   PAPERLESS_CONSUME=/tmp
   PAPERLESS_PASSPHRASE=THISISNOTASECRET
   PAPERLESS_SECRET=paperless
   PAPERLESS_EMAIL_SECRET=paperless
+
+[coverage:paths]
+source = ./

src/tox.ini

@@ -1,22 +0,0 @@
-# Tox (http://tox.testrun.org/) is a tool for running tests
-# in multiple virtualenvs. This configuration file will run the
-# test suite on all supported python versions. To use it, "pip install tox"
-# and then run "tox" from this directory.
-
-[tox]
-skipsdist = True
-envlist = py34, py35, py36, pycodestyle
-
-[testenv]
-commands = pytest
-deps = -r{toxinidir}/../requirements.txt
-
-[testenv:pycodestyle]
-commands=pycodestyle
-deps=pycodestyle
-
-[pycodestyle]
-exclude=
-  .tox,
-  migrations,
-  paperless/settings.py