Attempt to fix #110, using Travis feedback

Author: dayures

Diff for: .travis.yml

@@ -1,5 +1,9 @@
 # http://travis-ci.org/RDFLib/sparqlwrapper
 
+branches:
+  except:
+    - gh-pages
+
 sudo: false
 
 language: python
@@ -8,12 +12,15 @@ python:
     - 2.7
     - 3.4
     - 3.5
-    - 3.6
     - pypy
 
 # Enable 3.7 and 3.8-dev without globally enabling sudo and dist: xenial for other build jobs
 matrix:
   include:
+    - python: 3.6
+      env: ENV=py36
+      before_install:
+         - pyenv global 3.6
     - python: 3.7
       dist: xenial
       sudo: true