Apply linting to the CFN templates through cfn-lint

[neoghostz]

Idea behind this would be to enforce the strongly typed values for certain resources.
At present the following are put as Int rather than Strings
RDS:
Type: "AWS::RDS::DBInstance"
Properties:
AllocatedStorage: 100
BackupRetentionPeriod: 7
Port: 3306

Could be possibly a bug between cfn-lint and the Cloudformation JSON spec.