Being able to configure test page ready timeout

When executing a bigger test-suite, which is using Jasmine and RequireJS, it can happen that the fixed timeout of 5s is not enough until the test-page is ready (Executing the BonsaiJS test-suite with Chrome lead to the following result: https://saucelabs.com/tests/9a7e8746dd04459b84b79faa254366bd). This pull request adds the capability to configure that timeout through `testReadyTimeout`.

It additionally includes fixes for the `README`.