Add real world test data

[dyve]

We are looking for

• "real world" data, so not generated for the purpose of being an example;
• come from software that is in use by ringing schemes;
• both ringing and recovery events.

Because this will be open source test data, it is important that the owner of the data agrees that this data will be shared under the BSD-3-Clause license.

[r-vd-woude]

Are you still looking?
I can ask and see if we could supply some.

How many records would you need?

EDIT:
And thank you for making the library, it already proofed quite useful for me!