made host configurable (for running with PhantomJS in cloud9 IDE)

I made the host configurable in order to run testacular with PhantomJS in cloud9 IDE (see  https://groups.google.com/forum/#!topic/testacular/t-zCjt4zuO8). 

The testacular.conf.js file of the the AngularJS foodme app must include the following entries in order to run the the unit tests in cloud9: 
browsers = ['PhantomJS'];
host = process.env.IP;
port = process.env.PORT;
runnerPort = 0;

Additionally, PhantomJS must be installed with "npm install phantomjs".