systemd unit on CentOS 7 fails to start

[jtognazzi]

Because of 4f88a66 the selenium systemd unit is failing to start.
The problem seems to be with the quoting of the xvfb-run arguments.

Besides the integration tests failed to notice the failure because the systemd start command doesn't return any error.

Looking at the forks of this project, I found that @MassiveHiggsField has fixed these in his project https://github.com/MassiveHiggsField/ansible-role-selenium

@MassiveHiggsField do you plan to do a pull request ?

[MassiveHiggsField]

Already done #44

[rmeleromira]

This can also be fixed by escaping the spaces for the exec arguments
selenium_xvfb_args: "--server-args='-screen\\ 0,\\ 1920x1080x24'"