Implement Manager service.

Implement RPC service to work with plugins and DB.
Base plugin class added.

Implements: blueprint lease-manager
Change-Id: Icbed7fabef6c0673c62f67017e5e9cd8d257b5ee

requirements.txt

@@ -3,10 +3,12 @@ pbr>=0.5.21,<1.0
 eventlet>=0.13.0
 Flask>=0.10,<1.0a0
 iso8601>=0.1.4
+kombu>=2.4.8
 oslo.config>=1.2.0
 python-novaclient>=2.15.0
 netaddr
 python-keystoneclient>=0.3.2
 Routes>=1.12.3
 SQLAlchemy>=0.7.8,<=0.7.99
+stevedore>=0.10
 WebOb>=1.2.3,<1.3a0