MQTT file post

Feature Requests
1

Request: Post a file over MQTT.
Use case: posting an image to multiple instances of HASS which each implement mqtt camera

Simply requires:

with open('image.jpg', "rb") as imageFile:
     myFile = imageFile.read() 
     data = bytearray(myFile) 

client.publish('dev/camera', data, mqttQos, mqttRetained)