[py] Printing stdout and stderr to the log to investigate why geckodriver can't start

Author: barancev

py/tox.ini

@@ -10,7 +10,7 @@ commands =
   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}-remote: py.test --driver=Remote {posargs}
+  py{27,36}-remote: py.test -s --driver=Remote {posargs}
   py{27,36}-safari: py.test --driver=Safari {posargs}
   py{27,36}-chromiumedge: py.test --driver=ChromiumEdge {posargs}
 install_command = pip install -v --no-index --find-links=../third_party/py {opts} {packages}