Added http endpoint to list all users on a list (#87)

REST-Tests/auth.http

@@ -3,7 +3,7 @@ POST http://localhost:8080/api/v1/login
 Content-Type: application/json
 
 {
-  "username": "user6",
+  "username": "user3",
   "password": "1234"
 }
 

REST-Tests/lists.http

@@ -5,7 +5,7 @@ Authorization: Bearer {{auth_token}}
 ###
 
 # Get one list
-GET http://localhost:8080/api/v1/lists/1172
+GET http://localhost:8080/api/v1/lists/3
 Authorization: Bearer {{auth_token}}
 
 ###
@@ -82,11 +82,11 @@ Authorization: Bearer {{auth_token}}
 ###
 
 # Give a user access to that list
-PUT http://localhost:8080/api/v1/lists/1172/users
+PUT http://localhost:8080/api/v1/lists/3/users
 Authorization: Bearer {{auth_token}}
 Content-Type: application/json
 
-{"user_id":1, "right":1}
+{"userID":"user4", "right":1}
 
 ###
 
@@ -169,3 +169,9 @@ Content-Type: application/json
 }
 
 ###
+
+# Get all users who have access to a list
+GET http://localhost:8080/api/v1/lists/3/users
+Authorization: Bearer {{auth_token}}
+
+###