ReferralInida usecases developed.

1. Signup:
   Method: POST
   URL :   http://localhost:8080/referralindia/signup
   Example Payload :  {"personalEmail": "[email protected]" , "password" : "xxxx", "firstName" : "xxxxx" , "lastName": "xxxxx"}


2. Login:
   Method: GET
   URL   : http://localhost:8080/referralindia/login?username=xxxx&password=xxxxx
   

3. Method : DELETE
   URL    : http://localhost:8080/referralindia/logout
   Header value : secretKey : xxxxx