Switch to a batch IMU message

We only send in batches.  We would also like to forward these messages
across the network to the logger.  The resulting 2000 hz wakeups are
swamping message_gateway, and it isn't worth adding a batch forwarding
mode yet.

Change-Id: I2c2f5bc021a660e932e086965e10bc92f27e2ec1
diff --git a/y2020/BUILD b/y2020/BUILD
index 8beb799..58a99ce 100644
--- a/y2020/BUILD
+++ b/y2020/BUILD
@@ -169,6 +169,7 @@
         visibility = ["//visibility:public"],
         deps = [
             "//aos/events:config",
+            "//frc971/control_loops/drivetrain:config",
         ],
     )
     for pi in [