Rendering

review:
====
- [x] Show you how to state it is done :) (just edit that to add the 'x')
- [x] remove trailing witespaces
- [x] s/ACCEPTABILITY/duration_tolerance/ ?
- [ ] We do not properly see transitions value on schemes in test_transition

Media files generation:
- [x] Check that everything whent ok
- [ ] Make sure we have elements before generating/testing the format
- [ ] You should use gst_check_run_suite instead of srunner_run_all

$make distcheck

    Unexpected critical/warning: ges_layer_add_asset: assertion `GES_IS_ASSET (asset)' failed
    Unexpected critical/warning: ges_layer_add_asset: assertion `GES_IS_ASSET (asset)' failed
    Unexpected critical/warning: GError set over the top of a previous GError or uninitialized memory.
    This indicates a bug in someone's code. You must ensure an error is NULL before it's set.
    The overwriting error message was: Resource not found.
    0%: Checks: 6, Failures: 6, Errors: 0
    gstcheck.c:75:F:render:test_basic_render:0: Unexpected critical/warning: ges_layer_add_asset: assertion `GES_IS_ASSET (asset)' failed
    gstcheck.c:75:F:render:test_effect_rendering:0: Unexpected critical/warning: ges_layer_add_asset: assertion `GES_IS_ASSET (asset)' failed
    gstcheck.c:75:F:render:test_transition:0: Unexpected critical/warning: GError set over the top of a previous GError or uninitialized memory.
    This indicates a bug in someone's code. You must ensure an error is NULL before it's set.
    The overwriting error message was: Resource not found.
    gstcheck.c:75:F:render:test_basic_render:0: Unexpected critical/warning: ges_layer_add_asset: assertion   `GES_IS_ASSET (asset)' failed
    gstcheck.c:75:F:render:test_effect_rendering:0: Unexpected critical/warning: ges_layer_add_asset: assertion `GES_IS_ASSET (asset)' failed
    gstcheck.c:75:F:render:test_transition:0: Unexpected critical/warning: GError set over the top of a previous GError or uninitialized memory.
    This indicates a bug in someone's code. You must ensure an error is NULL before it's set.
    The overwriting error message was: Resource not found.
    FAIL: ges/render

- [ ] Make distcheck

This is details and it is very good stuff in overall :)