detect existing KeyPair to avoid failure on second cluster creation about eksctl

[errordeveloper]

It'd be nice to detect this error message and log as a warning and continue; or better use the aws CLI to query if the KeyPair exists for the given name first?

Something like that... but probably better to add unique name suffix based on checksum, and when such name exists, double check fingerprint, and error if it's absolutely not the same thing, but continue otherwise.

Also, if you want to make use of existing key, you can just pass --ssh-public-key EKS-eks1.

https://github.com/weaveworks/eksctl/blob/a71ba696af68b6656fccaa8e49e8f7c15715cee1/pkg/eks/auth.go#L26-L63

[errordeveloper]

I will take a stab at it.

[errordeveloper]

Arguably #105 is another way to fix this, but #106 is a plausible start (and needed anyway).