bug: properties that include special characters are not quoted in TS

[comcalvi]

Summary

TS can be emitted as:

   launchConfiguration.cfnOptions.metadata = {
      AWS::CloudFormation::Init: { // errors
        configSets: {
          MountConfig: [
            'setup',
            'mount',
          ],
        },

same steps #615, just change the type of AsgMaxSize from Number to String in the Parameters section of the template.