infracost: DMS pricing calculated on wrong region

I see support for DMS is added in #149 🙌

When running infracost v0.6.4 I see that DMS cost is calculated at $0.0720/hour, however, these resources run in eu-central-1 which have a different price.

• Price shown by infracost for t2.small (multi-az): $0.072/hour --> probably corresponds to price fetched from us-east-1?
• Price for t2.small (multi-az) in eu-central-1: $0.084/hour (According to: https://aws.amazon.com/dms/pricing/)

However, I see region support in the dms.go, but my golang knowledge is zero to none to be able to debug it properly.