Get Collaboration list completed.

wise-webapp/src/main/java/com/wisemapping/model/Collaboration.java

@@ -36,7 +36,7 @@ public class Collaboration {
         this.collaborator = collaborator;
 
         // Guarantee referential integrity
-        mindmap.addMindmapUser(this);
+        mindmap.addCollaboration(this);
         collaborator.addMindmapUser(this);
     }
 
@@ -60,6 +60,10 @@ public class Collaboration {
         return role;
     }
 
+    public void setRole(@NotNull CollaborationRole role) {
+        this.role = role;
+    }
+
     public boolean isOwner() {
         return getRole() == CollaborationRole.OWNER;
     }