Add updates to get code coverage working

[juwara0]

This project uses semver, please check the scope of this pr:

• #none# - documentation fixes and/or test additions
• #patch# - backwards-compatible bug fix
• #minor# - adding functionality in a backwards-compatible manner
• #major# - incompatible API change

CHANGELOG

• Updated the travis.yml and package.json to run code coverage

[coveralls]

Changes Unknown when pulling a15bc68 on juwara0:fixCoverage into ** on ciena-frost:master**.

[juwara0]

👍

[juwara0]

Ember 2.11.3 introduced a BUGFIX: emberjs/ember.js#14898 that is is causing tests with .to.throw() to fail. There is an issue open to update ember-mocha: emberjs/ember-mocha#141 which may end up being moved to chai that may fix this issue for us. In the meantime, I am pinning to Ember 2.11.2 until we see how this plays out.