aws/request: Add retry support for  RequestTimeoutException (#1158)
aws/request: Add retry support for  RequestTimeoutException (#1158)

Adds support for retrying RequestTimeoutException error code that is returned by some services.

Fix #1155
xibz/aws-sdk-go,zmarois/aws-sdk-go,yxd-hde/aws-sdk-go,xibz/aws-sdk-go,myshen/aws-sdk-go,calgaryscientific/aws-sdk-go,agworld/aws-sdk-go,xibz/aws-sdk-go,yxd-hde/aws-sdk-go,myshen/aws-sdk-go,zmarois/aws-sdk-go,zmarois/aws-sdk-go,yxd-hde/aws-sdk-go,aws/aws-sdk-go,radeksimko/aws-sdk-go,calgaryscientific/aws-sdk-go,agworld/aws-sdk-go,yxd-hde/aws-sdk-go,radeksimko/aws-sdk-go,calgaryscientific/aws-sdk-go,calgaryscientific/aws-sdk-go,agworld/aws-sdk-go,myshen/aws-sdk-go,radeksimko/aws-sdk-go,zmarois/aws-sdk-go,radeksimko/aws-sdk-go,jasdel/aws-sdk-go,xibz/aws-sdk-go,agworld/aws-sdk-go,myshen/aws-sdk-go