🎨 blacken code and clean up test-env install, introduce pre-commit

.pre-commit-config.yaml

@@ -0,0 +1,18 @@
+repos:
+  - repo: local
+    hooks:
+      - id: black
+        name: black
+        language: system
+        entry: black
+        types: [python]
+      - id: isort
+        name: isort
+        language: system
+        entry: isort -y
+        types: [python]
+      - id: flake8
+        name: flake8
+        language: system
+        entry: flake8
+        types: [python]

.travis.yml

@@ -16,8 +16,10 @@ before_install:
   - pip install -U pip
   - pip install codecov
 install:
-  - pip install  ".[test]" .
+  - pip install -r requirements-dev.txt
+  - pip install -e .
 script:
+  - pre-commit run -a
   - klangbecken init -d $KLANGBECKEN_DATA
   - coverage run --source=klangbecken -m unittest discover
   - flake8

README.md

@@ -2,6 +2,7 @@
 
 [![Build Status](https://travis-ci.org/radiorabe/klangbecken.svg?branch=master)](https://travis-ci.org/radiorabe/klangbecken)
 [![Coverage Status](https://codecov.io/gh/radiorabe/klangbecken/branch/master/graph/badge.svg)](https://codecov.io/gh/radiorabe/klangbecken)
+[![Codestyle Black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
 
 ## Description
 This repo contains two parts of the RaBe-Klangbecken infrastructure: