Test on Rhino, Ringo, Narwhal and PhantomJS on Travis
Fix errors for testing on Node and Istanbul
Remove the "Anticipated ES 6 Additions" test.
Add a separate test for trailing decimal points.

This detects Mozilla Rhino 1.7R3-R4, which supports trailing decimal
points and trailing commas in array and object literals.

Closes #46.
Update Spec and `marked`.
Fix PhantomJS and Rhino tests for Travis.
Ignore failing `istanbul` tests on Travis.
Use process exit codes to report test failures.
Remove `istanbul` from the test matrix. See #47.
Update tests to run properly on PhantomJS
Allow tests to pass in PhantomJS
Add minified json3 to component
Revert to older PhantomJS tests and optimize json3
Update download links and add cdn links to readme [ci skip]
JSON v3.2.6.
Update download links. [ci skip]