Replacement jockey wheels for Brompton

###logfile
2018-06-24: initial version. Neither printed nor tested yet.

###Summary

I created these jockey wheels because I got a used Brompton rear derailleur with worn-out jockey wheels. These jockey wheels will be redesigned in a later stage for a special purpose. More to be announced here!

###Warning:
* This is not a commercial product. I did not test it.
* Please feel *very* free to give suggestions, comments etc. if something doesn't fit!