Apply persistence layer transformations to teams type

[Re #1611]

* The teams properties are used internally as keywords so before
inserting into the db and before returning to callers we should
transform all the values of teams key into keywords.

backend/src/gpml/db/plastic_strategy/team.clj

@@ -16,11 +16,15 @@
   [ps-team-member]
   (-> ps-team-member
       (util/update-if-not-nil :role name)
-      (util/update-if-not-nil :teams util.pgsql/->JDBCArray "plastic_strategy_team_type")))
+      (util/update-if-not-nil :teams (comp
+                                      #(util.pgsql/->JDBCArray % "plastic_strategy_team_type")
+                                      #(map name %)))))
 
 (defn- p-ps-team-member->ps-team-member
   [p-ps-team-member]
-  (util/update-if-not-nil p-ps-team-member :role keyword))
+  (-> p-ps-team-member
+      (util/update-if-not-nil :role keyword)
+      (util/update-if-not-nil :teams #(map keyword %))))
 
 (defn add-ps-team-member
   [conn ps-team-member]