Simplify Hue for new users

- Sample config auto-discoveres Bridge IP
- Username left blank so that the server will prompt you
- Hue platform walks you through username creation (in as friendly a
way currently possible)

config-sample.json

@@ -25,8 +25,7 @@
         {
             "platform": "PhilipsHue",
             "name": "Phillips Hue",
-            "ip_address": "127.0.0.1",
-            "username": "252deadbeef0bf3f34c7ecb810e832f"
+            "username": ""
         },
         {
             "platform": "ISY",