[py] At attempt to run tests without xdist. For unknown reason travis can't start a driver for the very first test on gw1, lets' check if the job will work without xdist.

Author: barancev

py/tox.ini

@@ -7,7 +7,7 @@ commands =
   py{27,33,34,35,36}-unit: py.test -n=auto {posargs:test/unit}
   py{27,36}-chrome: py.test -n=auto --driver=Chrome {posargs}
   py{27,36}-edge: py.test --driver=Edge {posargs}
-  py{27,36}-firefox: py.test -n=auto --driver=Firefox {posargs}
+  py{27,36}-firefox: py.test --driver=Firefox {posargs}
   py{27,36}-ie: py.test --driver=Ie {posargs}
   py{27,36}-marionette: py.test --driver=Marionette {posargs}
   py{27,36}-phantomjs: py.test -n=auto --driver=PhantomJS {posargs}