Log zigbee2mqtt version information to bridge/config (#1267)

* add coordinator_firmware to bridge/config

* Add zigbee2mqtt version and commit

* Whoops

lib/zigbee.js

@@ -87,10 +87,14 @@ class Zigbee {
 
     logStartupInfo() {
         logger.info('zigbee-shepherd started');
-        logger.info(`Coordinator firmware version: '${this.shepherd.info().firmware.revision}'`);
+        logger.info(`Coordinator firmware version: '${this.getFirmwareVersion()}'`);
         logger.debug(`zigbee-shepherd info: ${JSON.stringify(this.shepherd.info())}`);
     }
 
+    getFirmwareVersion() {
+        return this.shepherd.info().firmware.revision;
+    }
+
     softReset(callback) {
         this.shepherd.reset('soft', callback);
     }