Add kLog camera command.

Change-Id: Ica73c88ca38b1fc5dc505ce61553d16772270644
diff --git a/y2019/jevois/structures.h b/y2019/jevois/structures.h
index 9c74b11..fcf1ebe 100644
--- a/y2019/jevois/structures.h
+++ b/y2019/jevois/structures.h
@@ -144,6 +144,8 @@
   // Send As, which triggers the bootstrap script to drop directly into USB
   // mode.
   kAs,
+  // Log camera images
+  kLog,
 };
 
 // This is all the information sent from the Teensy to each camera.