add gulp-mocha library and task for testing

gulpfile.js

 var gulp = require('gulp');
+var mocha = require('gulp-mocha');
 
 gulp.task('default', function() {
 
 });
+
+gulp.task('test', function(){
+  gulp.src('test/test.js', {read: false})
+    .pipe(mocha())
+    .once('error', function(){
+      process.exit(1);
+    })
+    .once('end', function(){
+      process.exit();
+    })
+});

package.json

@@ -29,6 +29,7 @@
     "chai": "^3.5.0",
     "chai-http": "^3.0.0",
     "gulp": "^3.9.1",
+    "gulp-mocha": "^3.0.1",
     "mocha": "^2.5.3"
   }
 }