Add pre-commit files and linting using pre-commit

.pre-commit-config.yaml

@@ -0,0 +1,24 @@
+repos:
+-   repo: https://github.com/ambv/black
+    rev: 18.6b4
+    hooks:
+    -   id: black
+        args: [--safe, --quiet]
+        language_version: python3.6
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v1.3.0
+    hooks:
+    -   id: trailing-whitespace
+    -   id: end-of-file-fixer
+    -   id: check-yaml
+    -   id: debug-statements
+    -   id: flake8
+-   repo: local
+    hooks:
+    -   id: rst
+        name: rst
+        entry: rst-lint --encoding utf-8
+        files: ^(CHANGELOG.rst|HOWTORELEASE.rst|README.rst|changelog/.*)$
+        language: python
+        additional_dependencies: [pygments, restructuredtext_lint]
+        python_version: python3.6