Implements iChain authentication

db/migrate/20141104131625_generate_username.rb

@@ -0,0 +1,18 @@
+class GenerateUsername < ActiveRecord::Migration
+  class TempUser < ActiveRecord::Base
+    self.table_name = 'users'
+    attr_accessible :username, :email
+  end
+
+  def change
+    TempUser.all.each do |user|
+      if user.username.blank?
+        username = user.email.split('@')[0]
+        if TempUser.find_by(username: username)
+          username = username + user.id.to_s
+        end
+        user.update_attributes(username: username)
+      end
+    end
+  end
+end