Add matrix backend and relevant config generation

backends/matrix.py

@@ -0,0 +1,12 @@
+from matrix_client.client import MatrixClient
+from matrix_client.api import MatrixHttpApi
+
+
+def send(config, message):
+    if 'token' in config:
+        token = config["token"]
+    else:
+        token = MatrixClient(config["server"]).login(config["username"],
+                                                     config["password"])
+    bot = MatrixHttpApi(config["server"], token=token)
+    bot.send_message(config["room_id"], message)