update travis settings

Author: leVirve

.travis.yml

@@ -1,11 +1,12 @@
 language: python
+cache: pip
 
 python:
   - "3.4"
+  - "3.5"
 
 install:
   - pip install -r requirements.txt
 
 script:
-  - python test.py
-
+  - python demo.py