Bitfab multi color keychain

[Bitfab](http://bitfab.io)'s keychain. We are a 3D printing service based in Spain and we often give this keychain to our customers.

Printed used the Pause at height plugin in Cura 15. Pause the print at 2.21mm and change filament from teal to white.

We have also made a short video of how the keychains are printed in batches of 10 units: https://www.youtube.com/watch?v=pGpexFLthi8&feature=youtu.be