Request: kafka - add ability to create more partitions

[karelbilek]

Describe the bug
Currently, you can create only topics with one partition.

All topics now have 1 partition and that's hard-coded.

To Reproduce
Create kafka with topics. They all have 1 partition, it's here in the code

gnomock/preset/kafka/preset.go

Line 212 in 6bb416a

NumPartitions: 1,

(After I get gnomock running, I will try to make a PR that will add this functionality)

[orlangure]

Hey @karelbilek and thank you for reporting this. It would be great if you could implement this, just like you did with a few other issues so far. Thanks for your work!

[karelbilek]

OK, you have it in the PR