Update Travis config

Travis isn't supporting Python 3.7 yet

Author: cmlccie

.travis.yml

@@ -4,7 +4,7 @@ python:
   - "2.7"
   - "3.5"
   - "3.6"
-  - "3.7"
+#  - "3.7"  It doesn't look like Travis is supporting v3.7 yet
 install: "script/setup"
 script: "script/ci"
 cache: pip