TestHandler 101

Testhandler still in rudimentary stages although it reads the tests property, parses it and then evals it (uses VM). 
Best way to run `mocha tests/TestResponseHandler.js`.
Need more thorough tests. To get more clarity on sandbox environment and variables refer to http://getpostman.com/docs/jetpacks_writing_tests.

PS: We should use console.log instead of process.write in logger so that we get a newline. Run the above command to see what I'm talking about.