Basic Travis CI setup

[cmorse]

I made a basic travis.yml file for #652. The build finishes well within their stated time limit of 50 minutes (or 10 minutes with no log output). I tested it, and it fails when there are syntax errors in the JavaScript, or documentation generation. I wasn't sure how to get documentation generation to generate warnings, so I don't know what will happen with that.

For it to work you have to follow the instructions at: http://about.travis-ci.org/docs/user/getting-started/

You can see the output from travis-ci for this branch here: https://travis-ci.org/cmorse/cesium/builds/8624560

[shunter]

This is great, thanks for getting it working. Can you add jsHint to the ant command line before release, and switch to node 0.10 which should be a bit faster?

[cmorse]

@shunter Ah, I didn't know that the release ant command didn't run jsHint. I changed that.

[cmorse]

I also experimented with getting it to print a message when CHANGES.md has not been updated. Unfortunately, right now Travis doesn't support a warning status for a build, so all I could do was print a message to the console. I just had it run this code:

if ! git diff --name-only $TRAVIS_COMMIT_RANGE | grep -q "CHANGES.md"; then
  echo "WARNING: Did you forget to update CHANGES.md?"
fi

I'll leave it up to you guys if you want to include that check or not.

[shunter]

Yeah, I can't find any way to do warnings, or have it attach comments to pull requests. I'll just merge this as-is, and we can add more checks in the future if we can find a way do to so.