Change library from bluepy to Bleak (with async) (#32)

* Update __init__.py

* Basic framework for bleak conversion.

* Update __init__.py

* Fix methods that return static data.

* Fixed last few functions.

* Ensure CaSe for discovery data, connect_lock for sensitive functions.

-No passive scan mode available so I removed references.

* Updated with latest changes on pyswitchbot

* Update messages to latest released version.

* Rework get device by type functions.

* Add missing model key.

* Update __init__.py

* Update __init__.py

* Update __init__.py

* Update __init__.py

* Update __init__.py

* Restructure for non blocking async.

* Attempt to improve reliability on weak signal device.

* Update __init__.py

* Update __init__.py

* Update __init__.py

* Update __init__.py

* Update __init__.py

* Update __init__.py

* A fix for a few dict keys being overwritten.

* Replace sleep with asyncio sleep.

* oops, forgot to await asyncio.sleep.

* Should probably keep the connect_lock on this function.

* Remove client.read_gatt_char, as notification is already in memory after writing.

setup.py

@@ -3,8 +3,8 @@
 setup(
     name = 'PySwitchbot',
     packages = ['switchbot'],
-    install_requires=['bluepy'],
-    version = '0.13.3',
+    install_requires=['bleak'],
+    version = '0.14.0',
     description = 'A library to communicate with Switchbot',
     author='Daniel Hjelseth Hoyer',
     url='https://github.com/Danielhiversen/pySwitchbot/',