Add testing infrastructure using jest

Added simple test to illustrate how to use jest with react.

jest/preprocessor.js

@@ -0,0 +1,12 @@
+var babelJest = require('babel-jest');
+var webpackAlias = require('jest-webpack-alias');
+
+module.exports = {
+  process: function(src, filename) {
+    if (filename.indexOf('node_modules') === -1) {
+      src = babelJest.process(src, filename);
+      src = webpackAlias.process(src, filename);
+    }
+    return src;
+  }
+};