Replace pre-commit with tox for black

Author: BeyondEvil

.pre-commit-config.yaml

@@ -10,6 +10,15 @@ jobs:
       addons: skip
       env: TOXENV=flake8
 
+    -
+      name: Formatting
+      python: 3.7
+      dist: xenial
+      sudo: required
+      before_install: skip
+      addons: skip
+      env: TOXENV=black
+
     -
       name: Docs
       python: 3.7

.travis.yml

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py{27,36,37,py,py3}, docs, flake8
+envlist = py{27,36,37,py,py3}, docs, flake8, black
 
 [testenv]
 passenv = PYTEST_ADDOPTS
@@ -28,6 +28,12 @@ basepython = python
 deps = flake8
 commands = flake8 {posargs:.}
 
+[testenv:black]
+skip_install = true
+basepython = python
+deps = black
+commands = black --check {posargs:.}
+
 [flake8]
 max-line-length = 88
 exclude = .eggs,.tox,docs