travis: Add Black

.travis.yml

@@ -14,8 +14,15 @@ python:
 
 matrix:
   include:
+    - name: Black
+      language: python
+      python: 3.8
+      install:
+        - pip install black
+      script:
+        - black --check --diff .
+
     - name: 32bit build
-      sudo: required
       language: python
       services:
         - docker

Makefile

@@ -2,6 +2,10 @@
 all: cython
 	python setup.py build_ext -i -f
 
+.PHONY: black
+black:
+	black .
+
 .PHONY: cython
 cython:
 	cython --cplus msgpack/_cmsgpack.pyx