Remove die_if_not_set check for var user_roles

Since the later logic will add role if the user role is not
found. "die_if_not_set" check will exit the main script.

Closes-Bug: #1389714

Change-Id: I995cf357d09267fee55e44575e3e301bcffebca3
Use RPC directly for software deployment operations

This change replaces heatclient REST calls with RPC calls when
creating, fetching or deleting software deployments.

Change-Id: If81b68717bd2f9d9be1291c07b18626493c9b5cc
Partial-blueprint: software-config-trigger
Merge "Use RPC directly for software deployment operations"
Merge "Remove die_if_not_set check for var user_roles"