Remove assert code?

[toshi0383]

Hi useful library!

Issue

I use 1.5.4 (via CocoaPods) and sometimes have crash on assert. I don't want this behavior as it works fine without these assertion, so re-installed via Carthage so assert is always disabled in Release build.

Proposal

Can we remove these assertions? We might want to ensure these conditions by writing tests or using custom build flags... etc, not affecting in customer(developers) side. Thoughts?