Soda Stream Adapter EU

This is an adapter for the EU Sodastream machine.

I printed a couple of other adapters but they didn't fit.
There are more Sodastream types than I can think of.

So I created my own one.
- suited for normal plastic drink bottle with a DIN 28 thread
- suited for the sodastream in the picture.
- the adapter is modelled from the original sodastream bottles.
- also added a test for the DIN 28 thread

I added a better version after some testing, it can be printed without supports.

Let me know if it worked for you.