Add zoom message.

* Improved tests.

* Refactored for testability. Updated messages. Completed tests.

* Fixed lint.

* Changes from review.

* Added detach for resize event.

* Fixed typo.
Merge pull request #106 from makyo/develop

This adds a message when the viewport is 1024 pixels or below. There are tests for the message creation, but not for the resize/os functionality.

Rebased and merged for huwshimi

* Improved tests.
* Refactored for testability. Updated messages. Completed tests.
* Fixed lint.
* Changes from review.
* Added detach for resize event.
* Fixed typo.