Migrate deliteful tests to Intern 2.0.1

This PR upgrade all deliteful tests to intern 2.0.1 and uses a global setting (in the intern configuration file) to setup test timeout, poll timeout and poll interval for all functional tests.

The Travis CI build for this branch is green: https://travis-ci.org/ibm-js/deliteful/builds/34286908

The tests can also be run locally on iOS (100 % success) using appium.

There are issue when running the tests locally on Android using selendroid. I suggest to create a dedicated issue for that once the PR has been merged on the master branch.