Placement: Define root path explicitly

Default value of api_port and path will be updated soon[1]. This change
adds explicit definition of these parameters to use consistent path.

[1] d7b8c158f989f3ac7846ee3d935df39e8533cf10

Change-Id: Ie0e21f1691d3e4e1b69d3abace03d418e638fe45

deployment/placement/placement-api-container-puppet.yaml

@@ -164,6 +164,7 @@ outputs:
               - {get_param: Debug}
             placement::policy::policies: {get_param: PlacementPolicies}
             placement::wsgi::apache::api_port: '8778'
+            placement::wsgi::apache::path: '/placement'
             placement::wsgi::apache::ssl: {get_param: EnableInternalTLS}
             # NOTE: bind IP is found in hiera replacing the network name with the local node IP
             # for the given network; replacement examples (eg. for internal_api):