gitignore: ctags files
gitignore: ctags files

Ignore any tags files, for people who use ctags to browse ruby
code.

pantheon-systems/berkshelf-api,pingworks/berkshelf-api-binrepo-store,damacus/berkshelf-api,damacus/berkshelf-api,gueux/berkshelf-api,pingworks/berkshelf-api-binrepo-store,pantheon-systems/berkshelf-api,gueux/berkshelf-api,damacus/berkshelf-api,gueux/berkshelf-api,pantheon-systems/berkshelf-api,pingworks/berkshelf-api-binrepo-store