add more pre-commit checks

A summary of what the hooks do:
* `pyupgrade` - A tool (and pre-commit hook) to automatically upgrade syntax for newer versions of the language.
* `end-of-file-fixer` - Makes sure files end in a newline and only a newline.
* `check-docstring-first` - Checks for a common error of placing code before the docstring.
* `check-yaml` - Attempts to load all yaml files to verify syntax.
* `debug-statements` - Check for debugger imports and py37+ breakpoint() calls in python source.
* `check-ast` - Simply check whether files parse as valid python.
* `seed-isort-config` - Statically populate the `known_third_party` `isort` setting because `isort` sucks at figuring out which third party libs are used. (from author of `pre-commit`)

Author: basnijholt

.isort.cfg

@@ -0,0 +1,2 @@
+[settings]
+known_third_party = PIL,atomicwrites,holoviews,ipykernel,matplotlib,nbconvert,numpy,pytest,scipy,setuptools,skopt,sortedcollections,sortedcontainers,zmq

.pre-commit-config.yaml

@@ -1,16 +1,43 @@
 repos:
--   repo: https://github.com/ambv/black
-    rev: 19.3b0
-    hooks:
-    - id: black
-      language_version: python3.7
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v2.1.0
+    rev: v2.4.0
     hooks:
-    -   id: end-of-file-fixer
     -   id: trailing-whitespace
+    -   id: end-of-file-fixer
+    -   id: check-docstring-first
+    -   id: check-yaml
+    -   id: debug-statements
+    -   id: check-ast
 -   repo: https://gitlab.com/pycqa/flake8
-    rev: 3.7.8
+    rev: 3.7.9
     hooks:
     -   id: flake8
-        args: ['--max-line-length=500', '--ignore=E203,E266,E501,W503', '--max-complexity=18', '--select=B,C,E,F,W,T4,B9']
+        args:
+          - --max-line-length=500
+          - --ignore=E203,E266,E501,W503
+          - --max-complexity=18
+          - --select=B,C,E,F,W,T4,B9
+-   repo: https://github.com/ambv/black
+    rev: 19.10b0
+    hooks:
+    - id: black
+      language_version: python3.7
+-   repo: https://github.com/asottile/pyupgrade
+    rev: v1.25.2
+    hooks:
+    -   id: pyupgrade
+        args: ['--py36-plus']
+-   repo: https://github.com/pre-commit/mirrors-isort
+    rev: v4.3.21
+    hooks:
+    -   id: isort
+        args:
+          - --multi-line=3
+          - --trailing-comma
+          - --force-grid-wrap=0
+          - --use-parentheses
+          - --line-width=88
+-   repo: https://github.com/asottile/seed-isort-config
+    rev: v1.9.3
+    hooks:
+    -   id: seed-isort-config