fix old migration file names

db/migrate/20140617183708_create_sessions.rb

@@ -0,0 +1,12 @@
+class CreateSessions < ActiveRecord::Migration
+  def change
+    create_table :sessions do |t|
+      t.string :session_id, :null => false
+      t.text :data
+      t.timestamps null: true
+    end
+
+    add_index :sessions, :session_id
+    add_index :sessions, :updated_at
+  end
+end