deploy: Remove parallel from fabfile

Running with parallel on a multinode setup we bumped into a
fabric/paramiko bug that freezes deployment. Specifically
we got:

paramiko.transport:Success for unrequested channel! [??]

This seems to be related with issue:

fabric/fabric#19

So until someone fixes it, we remove parallelism from setup_cluster
and setup_vmc. This will make a multinode deployment obviously slower
but will not affect the basic use case of --autoconf.

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>

snf-deploy/snfdeploy/fabfile.py

@@ -69,7 +69,6 @@ def setup_env(args):
 
 # Helper methods that are invoked via fabric's execute
 
-@parallel
 @with_node
 def _setup_vmc(ctx):
     VMC = roles.get(constants.VMC, ctx)
@@ -88,7 +87,6 @@ def _setup_role(ctx, role):
     ROLE.setup()
 
 
-@parallel
 @with_cluster
 def _setup_cluster(ctx):
     execute(_setup_master, ctx, hosts=ctx.masters)