Add S3 naming conventions to genomics novpc tmplte

Port from Cromwell cloud stack file, still no actual validation on form.

Author: illusional

src/templates/aws-genomics-root-novpc.template.yaml

@@ -55,8 +55,13 @@ Parameters:
     Type: List<AWS::EC2::Subnet::Id>
     Description: 'Subnets you want your batch compute environment to launch in. We recommend private subnets. NOTE: Must be from the VPC provided.'
   S3BucketName:
-    Description: A S3 bucket name for storing analysis results
+    Description: >-
+      A S3 bucket name for storing analysis results.
+      The bucket name must respect the S3 bucket naming conventions 
+      (can contain lowercase letters, numbers, periods and hyphens).
     Type: String
+    AllowedPattern: "(?=^.{3,63}$)(?!^(\\d+\\.)+\\d+$)(^(([a-z0-9]|[a-z0-9][a-z0-9\\-]*[a-z0-9])\\.)*([a-z0-9]|[a-z0-9][a-z0-9\\-]*[a-z0-9])$)"
+    ConstraintDescription: "Must respect AWS naming conventions"
   ExistingBucket:
     Description: Does this bucket already exist?
     Type: String