provision/lxc: created InstallDeps method
provision/provision,testing/provisioner: added InstallDeps command to Provision interface

Also added Run command to provision.App interface, because InstallDeps
use this wrapper method to run a command in an app.
provision/juju/provisioner: adding InstallDeps method.
testing/provisioner.go: logging method call in InstallDeps
app/app: calling Provisioner.InstallDeps in app.InstallDeps
provision/docker/provisioner.go: Added InstallDeps method