Use same Nova Client throughout Fresh Instance Task

    Fixes bug where nova client was reinitialized many times during
    building of new instance

Fixes: bug 1207931

Change-Id: I965a6fa74f721a74f7632aa68963787d02103af5
Merge "Use same Nova Client throughout Fresh Instance Task"
Add RPM class implementation

implements blueprint rpm-integration

Change-Id: I4aa06c75b555d0c9ab54791b25c612bc5c5805fc
:q!Merge branch 'master' of https://github.com/openstack/trove