Move from Mocha to Nodeunit

* Test runner moved from Mocha to Nodeunit
* In ```test/unit/cli/generate.test.js``` added ``console.log`` hooking function, so now log output can be hooked easily

example from the file 

```JavaScript
...
  'should raise an error if the name of the app matches the name of an existing folder': function(test){
    test.expect(2);

    fs.mkdir(demoAppPath, function(err) {

      var unHookLog = hookLog(); // creating a hook function for console.log
      generate.generate(program);
      unHookLog();

      test.strictEqual( logs.length, 1, "'logs' should have length === 1" );
      test.strictEqual( logs[0].toString(), "Sorry the '"+ demoAppEndDir +"' directory already exists. Please choose another name for your app.", "Error messages should be equal");
      test.done(err);
    });
  },
...
```