Handle TOSCA relationship with 'type' keyword

TOSCA relationship can be explicitely provided with in-line reference or with
'type' keyword in the template. The current code only handles in-line reference.

Change-Id: Id5b38fef1b099f8170e2941b348637372665c8f9

translator/toscalib/nodetemplate.py

@@ -95,6 +95,8 @@ class NodeTemplate(EntityTemplate):
                         found_relationship_tpl = True
                 #create relationship template object.
                 if not found_relationship_tpl:
+                    if isinstance(relationship, dict):
+                        relationship = relationship.get('type')
                     for rtype in self.type_definition.relationship.keys():
                         if rtype.type == relationship:
                             explicit_relation[rtype] = related_tpl

translator/toscalib/tests/data/test_requirements.yaml

@@ -10,7 +10,8 @@ node_templates:
   my_app:
     description: >
       Specify multiple requirement via node and relationship keyword,
-      as an explicit relationship.
+      as an explicit relationship. Also demonstrates relationship with
+      type keyword and without it as an in-line reference.
     type: tosca.nodes.WebApplication.WordPress
     requirements:
       - req1:
@@ -18,7 +19,8 @@ node_templates:
           relationship: tosca.relationships.HostedOn
       - req2:
           node: mysql_database
-          relationship: tosca.relationships.ConnectsTo
+          relationship:
+            type: tosca.relationships.ConnectsTo
   mysql_database:
     description: Specify requirement via a capability as an implicit relationship.
     type: tosca.nodes.Database