Add GovCloud compatible CloudFormation template

[atkinsonm]

Is your feature request related to a problem? Please describe.

I would like to have an Infrastructure as Code approach to more easily configure GovCloud accounts for use with CloudCheckr.

Describe the solution you'd like

I would like to be able to launch a CloudFormation template like I do with standard accounts.

Describe alternatives you've considered

Manual process is the alternative but is not as friendly for customers to adopt.

[atkinsonm]

I will submit a PR for this