Merge pull request #485 from goldrush/develop

Develop
開発用gem追加
DKIM$BBP1~(B($B2>(B)
Merge pull request #487 from goldrush/master

本番サーバーでの修正を逆マージ
Merge pull request #486 from 18sasaki/develop

開発用gem追加
Merge branch 'develop' of https://github.com/goldrush/goldrush into develop
DKIMの設定をproduction.rbに移動
Merge pull request #488 from goldrush/master

DKIMの設定をproduction.rbに移動
Merge branch 'develop' of https://github.com/goldrush/goldrush into develop