Write to stdout as binary

This allows better redirection.

In python3, must write to sys.stdout.buffer.  AttributeError for the unlikely event of a python2 based node being deployed.

confluent_osdeploy/common/initramfs/opt/confluent/bin/apiclient

@@ -703,4 +703,7 @@ if __name__ == '__main__':
     elif checkonly:
         sys.stdout.write(mclient.check_connections())
     else:
-        sys.stdout.write(mclient.grab_url(sys.argv[1], data).decode())
+        try:
+            sys.stdout.buffer.write(mclient.grab_url(sys.argv[1], data))
+        except AttributeError:
+            sys.stdout.write(mclient.grab_url(sys.argv[1], data))