it"s 2018. Can js get the unique ID of a mobile device? 
 the requirement is like this. To achieve a mobile punch function, it is required that you cannot sign in on behalf of a user. A user is associated with a device. 
 if you change a colleague"s account to log in, it is not successful to sign in for a colleague. Here we need to get the unique ID of the device. Ladies and Gods, is there any way 
