Fix loading of description.yaml
Fix loading of description.yaml

The file include references to lava_dispatcher python modules that has been
rename (the 'lava_dispatcher.pipeline' module does not exist anymore).

Change-Id: I63bb2dfefbddb6c1af6e72009c38a5e7a687fee5

Linaro/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server