GitLab

Add option to use a custom image_id and flavor_id instead of getting
them from config file.

Get credentials for deployment from .kamakirc instead of config file.
Also, add option in config file indicating which cloud for kamaki to
use. Finally, add option in SynnefoCI to override the cloud from config.

Refs #4193

Add option for copying ssh keys to the created vm.

* override config file from env variable
* pep8 fixes
* do not display vm password
* fail if cloning repo fails
* do not use eval

Spawn VM to use as builder-slave.
Build packages inside this VM.
Deploy Synnefo using snf-deploy.
Run unit tests.
Run functional tests using burnin.