Rename migrations

db/migrate/1_create_media_objs_and_media_attachments.rb → db/migrate/1_create_whaleback_media_objs_and_media_attachments.rb

-class CreateMediaObjsAndMediaAttachments < ActiveRecord::Migration[5.1]
+class CreateWhalebackMediaObjsAndMediaAttachments < ActiveRecord::Migration[5.1]
   def change
-    create_table :media_objs do |t|
+    create_table :whaleback_media_objs do |t|
       t.attachment :file
       t.string     :type
-      
-      t.references :creator, polymorphic: true
+
+      t.references :creator, polymorphic: true, index: { name: :whaleback_poly_creator }
       t.timestamps
     end
 
-    create_table :media_attachments do |t|
+    create_table :whaleback_media_attachments do |t|
       t.string     :column_name
 
-      t.references :attached, polymorphic: true
+      t.references :attached, polymorphic: true, index: { name: :whaleback_poly_attached }
       t.references :obj
       t.timestamps
     end