In order to successfully build please follow these steps: I assume you already have installed node.js and ruby (in order to compile sass files).
1- open cmd in current project folder. 2- write the command 'npm update' 3- after the last command finished write this command 'bower update' 4- you can use these grunt commands 'grunt serve', 'grunt build' and 'grunt test'.
Run grunt for building and grunt serve for preview.
Running grunt test will run the unit tests with karma.