DemoBluetoothManager
封装API
蓝牙搜索设备
蓝牙当前设备
工程目录：
https://github.com/foolsparadise/DemoBluetoothManager
参考链接：
https://github.com/fuzheng0301/FZBluetooth
https://www.jianshu.com/p/c5f736a13479
http://blog.sina.com.cn/s/blog_61e26bcb0101ax34.html
https://blog.csdn.net/swibyn/article/details/52096665
https://www.oschina.net/question/2399354_240682
https://www.cnblogs.com/scaptain/p/4528230.html