title: How to log in the HyperLedger Composer webApp with different user other than admin
body: <p>I just started building a relatively simple supply-chain app by using HyperLedger Composer webApp. In my permission file, I will have several participants that specify which role can do what. It's easy to switch role inside the playground through the wallet. However, I can't find a way to switch at my Angular webApp. </p>
  
  <p>I thought it can be called through the System endpoint in the composer REST Server. But when I trying to "GET" from the /system/identities nothing show up, even I have created several participants. Can someone enlighten me with some examples?</p>
  
  <p>Thank you guys so much! </p>