Merge pull request #7035 from martenson/remove-sudo

Remove ``sudo: false`` from .travis.yml, it will stop being supported soon

.travis.yml

@@ -1,4 +1,3 @@
-sudo: false
 language: python
 python: 2.7
 os:
@@ -36,6 +35,10 @@ matrix:
     - env: TOX_ENV=py34-unit
       addons: *py3_addons
 
+before_install:
+  # Workaround for https://github.com/travis-ci/travis-ci/issues/7940
+  - sudo rm -f /etc/boto.cfg
+
 install:
   - set -e
   - pip install tox