frontend envrionment update

• Install nodejs in your local, we will use npm. After installing it, run the following command to check.

  npm -v

• Use npm to install all the resources we need for AngularJS2, run the following command in the direction your_dir/project/src/main/webapp/

  npm install

  ​

• some Bootstrap js functions not working
• add css styles to pages login, signup, homepage
• add job details page
• get jobinfo from server
• add post job page
• add user profile page
• update userinfo
• to be added