Move data migrations from rake tasks to gem

See #1298

db/data/20150707103801_refactor_contact_statuses.rb

@@ -1,15 +1,14 @@
-class RefactorContactStatuses < ActiveRecord::Migration
+class RefactorContactStatuses < ActiveRecord::Migration[5.1]
   def self.up
-    Contact.find_each do |contact|
-      statuses = []
-      contact.depricated_statuses.each do |ds|
-        statuses << ds.value
-      end
-      contact.update_column('statuses', statuses)
-    end
+    # Contact.find_each do |contact|
+    #   statuses = []
+    #   contact.depricated_statuses.each do |ds|
+    #     statuses << ds.value
+    #   end
+    #   contact.update_column('statuses', statuses)
+    # end
   end
 
   def self.down
-    raise ActiveRecord::IrreversibleMigration
   end
 end