Added test execution on Chrome browser. Updated grunt, grunt plugins. Fixed new ESLint warning.

[kibertoad]

No description provided.

[kibertoad]

3 tests are failing when executed on Chrome, but I'm not sure if that's not due to differences between PhantomJS and Chrome. Those can be looked at separately.

[obiot]

wow, that's great ! I was actually looking at karma the other day and was wondering if it would work as well with the travis build process (In this case Chrome is not really headless, compared to phantomJS)

[obiot]

failing tests are on:

• the ES6 Map polyfill (@see ES6 Collections tests are failing under Jasmine  #810), maybe we should just remove those tests, i don't know....
• pointerEvent, this one should work though as they are supposed to be supported since Chrome 55

Chrome 59.0.3071 (Windows 10 0.0.0) ES6 Collections test Map#set FAILED
        Expected true to equal false.
            at Object.<anonymous> (tests/spec/es6-collections.js:163:22)
        Expected Function to be undefined.
            at Object.<anonymous> (tests/spec/es6-collections.js:165:22)
        Expected Object({  }) not to equal Object({  }).
            at Object.<anonymous> (tests/spec/es6-collections.js:169:27)
Chrome 59.0.3071 (Windows 10 0.0.0) ES6 Collections test Map#forEach with mutations FAILED
        Expected undefined to equal '[1,3,0]'.
            at Object.<anonymous> (tests/spec/es6-collections.js:260:39)
Chrome 59.0.3071 (Windows 10 0.0.0) me.input Pointer Event PointerDown event triggering FAILED
        Error: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL.
Chrome 59.0.3071 (Windows 10 0.0.0): Executed 286 of 289 (3 FAILED) (skipped 3) (7.448 secs / 7.433 secs)

[kibertoad]

@obiot Note the karma-runner/karma-chrome-launcher#111 -> karma-chrome-launcher used in this PR already includes the 111, so making this CI-friendly should be a matter of just specifying a different launcher.