Fix breakage at head.

Change-Id: I2534de2575a6510fdd7df684ddfa0f4ca95ade49
diff --git a/y2019/jevois/BUILD b/y2019/jevois/BUILD
index fde8c12..e99a264 100644
--- a/y2019/jevois/BUILD
+++ b/y2019/jevois/BUILD
@@ -139,6 +139,7 @@
     name = "serial",
     srcs = ["serial.cc"],
     hdrs = ["serial.h"],
+    visibility = ["//visibility:public"],
     deps = [
         "//aos/logging",
     ],