Fixed: tns devices <platform> throws an exception

Author: Tsvetan Raikov

lib/commands/devices.ts

@@ -1,6 +1,8 @@
 export class DevicesCommand implements ICommand {
 
-	public allowedParameters: ICommandParameter[] = [];
+	constructor(private $stringParameter: ICommandParameter) {}
+
+	public allowedParameters: ICommandParameter[] = [this.$stringParameter];
 
 	public execute(args: string[]): IFuture<void> {
 		return $injector.resolveCommand("device").execute(args);