改變Estimote beacon的uuid

Here is how to do this:

1. First, start ranging for the beacons using startRangingBeaconsInRegion: with the ESTBeaconManager class: http://estimote.github.io/iOS-SDK/Classes/ESTBeaconManager.html

2. Then use connectToBeacon method in ESTBeacon class:  http://estimote.github.io/iOS-SDK/Classes/ESTBeacon.html

3. Finally change the UUID using
writeBeaconProximityUUID:withCompletion: method in ESTBeacon class:http://estimote.github.io/iOS-SDK/Classes/ESTBeacon.html

This way you can change:

- UUID only
- UUID and major
- UUID, major and minor