Added requirements.txt to travis.yml

Author: tcalmant

.travis.yml

@@ -10,6 +10,7 @@ sudo: false
 install:
   - pip install nose coverage coveralls
   - pip install pytest>=2.7.3 --upgrade
+  - pip install -r requirements.txt
 
 script:
   - nosetests -v --with-coverage --cover-package=javaobj tests