added makefile

.travis.yml

@@ -24,8 +24,10 @@ matrix:
     - python: "3.7"
     - python: "nightly"
 
-install: "pip install -r requirements.txt"
+install:
+  - make install
+
 script:
   - uname -a
   - pytest --version
-  - pytest
\ No newline at end of file
+  - make test
\ No newline at end of file

Makefile

+init:
+	pip install -r requirements.txt
+
+test:
+	pytest
+
+yapf:
+	find . -type f -name "*.py" | xargs yapf -i