2.0.0

• This is a fork. You can find the original project here.
• Now the codebase super strict, and it's covered with tests as much as possible. The original author is great, but the code was smelly :) It's sooo easy, and it took just one my evening... ;)
• I don't like wording "backoff" in the code. Yeah, it's fun but... I believe "retry" is more obvious. Sorry :)
• There is nothing wrong to use import instead of global namespace for function.
• At least my project has aliases for backward compatibility with the original. ;)