configurable default rate limiter backend

[StasEvseev]

Hello,

In my project I use rate limiter. And I need to have a possibilities to change it in test environment for example.

Here is one of the solutions.

Thanks for you time.

[StasEvseev]

@Bogdanp is there chance for you to check this PR?

[Bogdanp]

Yep. I'll try to take a look next week. Please don't forget to add yourself to the contributor list.

[Bogdanp]

Thanks! This has been merged with rebase and released.