AWS SDK v2 fork

[lzap]

Hey Marc,

we needed this writer with AWS SDK v2 and I was under time pressure so I forked your project to quickly build the library. I am opening an issue if you want to incorporate it back into v2 package perhaps?

https://github.com/lzap/cloudwatchwriter2

Apologies I don't have time to do proper PR at this point. Let me know if you decide to do that and I will happily archive my fork with instructions how to use v2 of your project. Thanks!