Support getting bulk playlists by permalink

Author: rickyrombo

api/swagger/swagger-v1.yaml

@@ -1084,7 +1084,7 @@ paths:
     get:
       tags:
       - playlists
-      description: Gets a list of playlists by ID
+      description: Gets a list of playlists by ID, UPC, or permalink
       operationId: Get Bulk Playlists
       parameters:
       - name: user_id
@@ -1101,6 +1101,15 @@ paths:
           type: array
           items:
             type: string
+      - name: permalink
+        in: query
+        description: The permalink(s) of the playlist(s)
+        style: form
+        explode: true
+        schema:
+          type: array
+          items:
+            type: string
       - name: upc
         in: query
         description: The UPC of the playlist(s)