Bump letter_opener from 1.8.0 to 1.8.1

Bumps letter_opener from 1.8.0 to 1.8.1.

Changelog

Sourced from letter_opener's changelog.

1.8.1

• Fix duplication of Rails tasks caused by LetterOpener's rake task file. (thanks zarqman)

Commits

• cb03dc8 Bump version.
• 0690de1 Update CHANGELOG.md
• 60f4629 Merge pull request #200 from zarqman/fix-dupe-rails-tasks
• 9469c63 fix duplication of rails tasks
• See full diff in compare view