No need for a virtualenv in TravisCI - already running in one

.travis.yml

@@ -26,11 +26,8 @@ env:
     - TOX_ENV=ansible-syntax
 
 install:
-  # Install a virtualenv for tox.
-  - virtualenv venv
-  - venv/bin/pip install -U pip
-  - venv/bin/pip install tox
+  - pip install tox
 
 script:
   # Run the tox environment.
-  - venv/bin/tox -e ${TOX_ENV}
+  - tox -e ${TOX_ENV}