OSMENG-992 - Implement create model activity

in NS Workflow.

An exception is raised if model already exists

Change-Id: I0000f98e2d6c1b458d3234ac83594b9ce5c86f26
Signed-off-by: Patricia Reinoso <patricia.reinoso@canonical.com>
diff --git a/osm_common/temporal_constants.py b/osm_common/temporal_constants.py
index 3b7c3eb..a953119 100644
--- a/osm_common/temporal_constants.py
+++ b/osm_common/temporal_constants.py
@@ -34,7 +34,8 @@
 ACTIVITY_DEPLOY_NS = "deploy-ns"
 ACTIVITY_UPDATE_NS_STATE = "update-ns-state"
 ACTIVITY_CHECK_NS_INSTANTIATION_FINISHED = "check-ns-instantiation-finish"
-ACTIVITY_CREATE_MODEL_IF_DOESNT_EXIST = "create-model-if-doesnt-exist"
+ACTIVITY_CREATE_MODEL = "create-model"
+ACTIVITY_GET_MODEL_INFO = "get-model-info"
 ACTIVITY_DEPLOY_CHARM = "deploy-charm"
 ACTIVITY_CHECK_CHARM_STATUS = "check-charm-status"
 ACTIVITY_CHANGE_NF_STATE = "change_nf_state"