Update to marko-cli

[abiyasa]

Change marko-devtools to marko-cli.

• Update test accordingly.
• Update syntax to ES6.

I have problem on renderResult.$() when it runs on browser. I got

1) components/color-picker/components/color-picker-header
       color-picker-header color:
     AssertionError: object tested must be an array, an object, or a string, but undefined given
      at Object.module.exports [as expectTypes] (static/browser-tests-runner/chai$3.5.0/lib/chai/utils/expectTypes.js:38:11)
      at Assertion.include (static/browser-tests-runner/chai$3.5.0/lib/chai/core/assertions.js:206:7)
      at Assertion.assert (static/browser-tests-runner/chai$3.5.0/lib/chai/utils/addChainableMethod.js:84:49)
      at Context.<anonymous> (static/browser-tests-runner/marko-color-picker$0.0.3/components/color-picker/components/color-picker-header/test.js:9:44)
      at Context.<anonymous> (static/browser-tests-runner/@marko/test$1.0.2/util/browser-tests-runner/setup.js:33:34)

However, it works when you run the test on the server, so I have to rename rendering test to test.server.js

To make the click testing work, you have to run it on browser so I have to use renderResult.component.el which will get the DOM element of the component. Once I get the DOM, I can click it or assert the class list for the rendering test.

TBH, I'm not sure if this is recommended pattern on using marko-cli. Any thoughts?