Shimon/ratelimit/add condition to rate limiter

[shimon-lb]

This PR include additions below:

1. Adding a condition to RateLimitDecorator that will allow 'bypassing' limit, in exceptional cases.
2. Unit test for conditional ratelimiter.
3. Add the ability to avoid rasing an exception in case limit was reached, but also, avoid calling the function.

[tomasbasham]

I'll merge this in this evening. Thanks a lot

[shimon-lb]

Thanks!