Add methods to handle video of tests

- createVideo method create a video from tests. 
- getEmbedVideoPlayer method create a html5 player for a video.

For instance, calling `createVideo` with this parameter : 130416_YS_KD4-r:3-c:1,130416_W6_KEE-r:8-c:1 create a comparison video between the first view of the run 3 of the test 130416_YS_KD4 and the first view of the run 8 of the test 1,130416_W6_KEE.

In result, the method returns a video id, for instance : 130416_36ed6e37013655a14b2b857cdccec99db72adcaa

Then, calling `getEmbedVideoPlayer` with this video id returns a HTML5 embedded player.