Support non-Commercial partitions

[mmehrten]

Some code in the repository explicitly references the "aws" partition - this limits functionality for non-commercial partitions like GovCloud.

amazon-redshift-udfs/stored-procedures/sp_cdc_DynamoDB_to_Redshift/sp_cdc_DynamoDB_to_Redshift.sql

Line 14 in b37a90a

role_string = 'arn:aws:iam::'+$2+':role/'+$1;