Try to combat Azure timeout with travis_wait

.travis.yml

@@ -64,7 +64,7 @@ install:
     - pip install coveralls
     - pip install codecov
 script:
-    - tox -r -e $TOX_ENV
+    - travis_wait 30 tox -r -e $TOX_ENV
 after_script:
     - |
       case "$TRAVIS_EVENT_TYPE" in