Removing old bitbot as we have a new bitbot package (#2479)

docs/extensions.md

@@ -36,10 +36,6 @@ Check out [microbit.org](http://microbit.org/resellers/) for more information on
   "name": "4tronix MiniBit",
   "url":"/pkg/4tronix/MiniBit",
   "cardType": "package"
-}, {
-  "name": "SRS BitBot",
-  "url":"/pkg/srs/pxt-bitbot",
-  "cardType": "package"
 }, {
   "name": "Sunfounder Sloth",
   "url":"/pkg/sunfounder/pxt-sloth",

targetconfig.json

@@ -46,7 +46,6 @@
             "CoderDojoOlney/pxt-olney",
             "PaulDFoster/pxt-microbit-GY521",
             "chevyng/pxt-ucl-junkrobot",
-            "srs/pxt-bitbot",
             "sparkfun/pxt-gamer-bit",
             "sparkfun/pxt-moto-bit",
             "sparkfun/pxt-weather-bit",