validate: Make it possible to run gst-validate-launcher on embedded device (that might not support python)

Submitted by Thibault Saunier @thiblahute

Link to original bug (#736137)

Description

The gst-validate-launcher is written in python, we should make sure that the tests can be run on embedded platforms, and hopefully even the ones that do not support python (android, iOS?).

For that we might want to launch the test through ssh?