Module usage doesn't appear to work with localhost

[anselmbradford]

Using a localhost address in https://github.com/cfpb/node-wcag#module-usage always passes and returns an empty array for errors and potentialProblems.

[zrrrzzt]

AChecker will not check localhost. The workaround is using localtunnel. Localtunnel however is only triggered in cli.js. We'll need to move this into index.js.

[contolini]

@zrrrzzt Do we want to bake localtunnel into this module? I kind of feel like it defeats the 'do one thing and only one thing' principle.

If you're testing localhost you can import localtunnel on your own:

var localtunnel = require('localtunnel');

localtunnel(port, function(err, tunnel) {
    wcag({uri: tunnel.url, id: 'xxxxxxxx'}, function(err, resp) {
      ...
    });
});

We should add better error handling, though, instead of returning no errors.

[zrrrzzt]

I do agree @contolini. Moving localtunnel into index seemed like a good idea for a few seconds. We should consider having an example like the one you just gave in the README