Please add support for missing regions

[liclac]

According to this list: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html
And this definition file: https://github.com/AdRoll/goamz/blob/master/aws/regions.go

This library's region support is somewhat spotty:

• us-east-1 - US East (N. Virginia)
• us-east-2 - US East (Ohio)
• us-west-1 - US West (N. California)
• us-west-2 - US West (Oregon)
• ca-central-1 - Canada (Central)
• eu-central-1 - EU (Frankfurt)
• eu-west-1 - EU (Ireland)
• eu-west-2 - EU (London)
• eu-west-3 - EU (Paris)
• ap-northeast-1 - Asia Pacific (Tokyo)
• ap-northeast-2 - Asia Pacific (Seoul)
• ap-northeast-3 - Asia Pacific (Osaka-Local)
• ap-southeast-1 - Asia Pacific (Singapore)
• ap-southeast-2 - Asia Pacific (Sydney)
• ap-south-1 - Asia Pacific (Mumbai)
• sa-east-1 - South America (São Paulo)

Discovered after I tried to use Docker Registry with a bucket in London ^^;;

I would add these myself, but I'm unsure of where to look up the required data. Will gladly help out if you can tell me though.

[alimoeeny]

Thanks @liclac please send a pr , most services use https://github.com/AdRoll/goamz/blob/master/aws/regions.go
there are exceptions if I remember but let's not worry about them.
I assume you know that this library is not meant to be used for new projects.