Allow reset codebuild access to custom nuke config template bucket

[morganpa]

Version information
Terraform version = 0.12.31
DCE deployed with terraform @ v0.33.8

Describe the bug

Not sure if this should be filed as a feature request or a bug.

When passing a value for variable reset_nuke_template_bucket and reset_nuke_template_key I'd expect the build to be given necessary permissions in that bucket. (Add optional policy attachment in modules/reset_codebuild.tf)

To Reproduce
1.

 $ cat main.tfvars
namespace                   = "xxxxx"
reset_nuke_template_bucket  = "somebucket"
reset_nuke_template_key     = "config.yaml"

cd modules
terraform init
terraform apply -var-file main.tfvars
cd .. # this is not in the documentation btw https://dce.readthedocs.io/en/latest/terraform.html
make deploy

3. dce accounts add ... trigger codebuild which should pull custom nuke config from 1

Expected behavior
Codebuild should be granted permissions at tf apply to access the bucket passed in variables.tf

Additional context
N/a