Now using macaddr datatype and added test for adding devices and displaynames

migrations/2_telemetry.sql

@@ -5,6 +5,6 @@ CREATE TABLE Telemetry (
     Voltage FLOAT,
     Temperature FLOAT,
     uptime INT NOT NULL,
-    device_id CHAR(32) NOT NULL,
+    device_id MACADDR NOT NULL,
     FOREIGN KEY (device_id) REFERENCES Devices(ID)
 );