added get telemetry

migrations/2_telemetry.sql

@@ -1,10 +1,10 @@
 -- Add migration script here
 CREATE TABLE Telemetry (
     timestamp TIMESTAMP NOT NULL,
-    Software_Version INT,
+    Software_Version INT NOT NULL,
     Voltage FLOAT,
     Temperature FLOAT,
-    uptime INT,
-    device_id CHAR(32),
+    uptime INT NOT NULL,
+    device_id CHAR(32) NOT NULL,
     FOREIGN KEY (device_id) REFERENCES Devices(ID)
 );