Creating the route for adding new keywords

Creating a new keyword results in a POST request to /api/keywords. Let's extend our spec accordingly:

it('should create a new keyword when receiving a POST request at \
 /api/keywords/', function (done) {
    var expected = {
      "_items": [ 
        {'id': 1, 'value':  'Aubergine', 'categoryID': 1},
        {'id': 2, 'value': 'Onion', 'categoryID': 1}
      ] 
    };
    var body = {
      'value': 'Onion',
      'categoryID': 1
    };

    async.series(
      [

        function(callback) {
          dbSession.insert(
            'category',
            {'name': 'Vegetable'},
            function(err) ...