deleteメソッドまで翻訳
Update CREDITS.md
general/error.html 翻訳完了
Merge pull request #347 from egmc/session-usage-method

deleteメソッドまで翻訳
Merge pull request #348 from seckie/patch-4

Update CREDITS.md
Merge pull request #349 from kenjis/fix_error

general/error.html 翻訳完了