travis: install script update

Author: userzimmermann

.travis.yml

@@ -7,9 +7,10 @@ python:
 
 install:
   - pip install -r requirements.txt
-  - zetup install
+  - pip install zetup[all]
   - pip install pytest
   - pip install tox
+  - pip install -e .
 
 script:
   - zetup pytest