Merge pull request #909 from hbrunn/10.0-green_2018-04-10

[FIX] higher python version, no system site packages

.travis.yml

@@ -1,8 +1,8 @@
 language: python
 
 python:
-  - "2.7"
-  
+  - "2.7.13"
+
 sudo: false
 cache: pip
 
@@ -24,9 +24,6 @@ env:
   - TESTS="1" ODOO_REPO="odoo/odoo"
   - TESTS="1" ODOO_REPO="OCA/OCB"
 
-virtualenv:
-  system_site_packages: true
-
 install:
   - pip install anybox.testing.openerp
   - git clone --depth=1 https://github.com/OCA/maintainer-quality-tools.git ${HOME}/maintainer-quality-tools