Get off off rails-assets

Just moving the things we currently use (and should drop in the ASAP) to vendor/assets

vendor/assets/javascripts/holderjs/test/runner.js

@@ -0,0 +1,37 @@
+var client = require('webdriverio');
+
+module.exports = function (options, cb) {
+    var retval = true;
+
+    client.remote({
+        'user': process.env.SAUCE_USERNAME,
+        'key': process.env.SAUCE_ACCESS_KEY,
+        'host': 'localhost',
+        'port': 4445,
+        'desiredCapabilities': {
+            'browserName': options.browserName,
+            'tunnel-identifier': process.env.TRAVIS_JOB_NUMBER,
+            'name': 'Holder.js Test',
+            'tags': [options.browserName]
+        }
+    })
+    .init()
+    .url('http://localhost:8000')
+    .execute(function () {
+        var expectImages = document.querySelectorAll('img').length - document.querySelectorAll('img[data-exclude]').length;
+        var renderedImages = document.querySelectorAll('img[data-holder-rendered]').length;
+        return {'expected': expectImages, 'rendered': renderedImages};
+    }, function (err, ret) {
+        var expected = ret.value.expected;
+        var rendered = ret.value.rendered;
+        console.log('Expected', expected);
+        console.log('Rendered', rendered);
+        if (expected !== rendered) {
+            retval = false;
+        }
+    })
+    .pause(15 * 1000)
+    .end(function () {
+        cb(null, retval);
+    });
+};