travis script is updated.

Author: shtaxxx

.travis.yml

@@ -6,14 +6,15 @@ python:
   - 2.7
   - 3.4
   - 3.5
+  - 3.6
 
 addons:
   apt:
     packages:
     - iverilog
 
 install:
-  - pip install pytest pytest-pythonpath pyverilog
+  - pip install pytest pytest-pythonpath pyverilog ipgen
 
 script:
   - python -m pytest tests examples