Generate correct route when :format segment is mandatory

Fixing https://github.com/enriclluelles/route_translator/issues/57
Add bundler installation path and gem build results to .gitignore
Merge branch 'format-segment' of github.com:khustochka/route_translator into khustochka-format-segment
Add bundler installation path for gemfiles to .gitignore
Merge branch 'khustochka-format-segment'