fix: fix set method to use map property

[aildermi]

Description

Bug was produced on an Android device using Chrome 34, which window.Map is not available. Error message Cannot set property 'TimeDisplay#updateTextNode_' of undefined was logged to console.
the set method in MapSham was using set_ property, which is not defined within MapSham class. map_ must be used instead.

Specific Changes proposed

Just changed src/js/utils/map.js file updating set method to use map_ instead of set_

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Change has been verified in an actual browser (Chrome, Firefox, IE)
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[welcome]

💖 Thanks for opening this pull request! 💖

Things that will help get your PR across the finish line:

• Run npm run lint -- --errors locally to catch formatting errors earlier.
• Include tests when adding/changing behavior.
• Include screenshots and animated GIFs whenever possible.

We get a lot of pull requests on this repo, so please be patient and we will get back to you as soon as we can.

[brandonocasey]

👍

[gkatsev]

Thanks, that's such a silly mistake.

[welcome]

Congrats on merging your first pull request! 🎉🎉🎉