Refactor ara-server into namespaced python modules

This is a structure that will allow us to install everything under
"ara" as separate packages but inside the same module.

For example, installing ara-server will provide ara.server and
ara.api.
Installing ara-clients will provide ara.clients, ara-plugins will
supply ara.plugins, etc.

Change-Id: I27ee431c4e5d946f558befc12937ba2f3c0d020b

setup.cfg

@@ -1,11 +1,11 @@
 [metadata]
-name = ara-backend
-summary = ARA Records Ansible backend
+name = ara-server
+summary = ARA Records Ansible API and Server components
 description-file =
     README.rst
 author = OpenStack Community
 author-email = openstack-dev@lists.openstack.org
-home-page = https://github.com/openstack/ara-backend
+home-page = https://github.com/openstack/ara-server
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -26,8 +26,11 @@ setup-hooks =
     pbr.hooks.setup_hook
 
 [files]
+namespace_packages =
+    ara.api
+    ara.server
 packages =
-    ara-backend
+    ara
 
 [build_sphinx]
 source-dir = doc/source
@@ -41,7 +44,6 @@ upload-dir = docs/html
 ignore_errors = True
 include =
     ara/*
-    api/*
 omit =
     /usr*
     setup.py