Convert control loop tests over to simulated event loop

This makes it so that we properly only use ShmEventLoop for running in
realtime on a robot.  Very nice.

Change-Id: I46b770b336f59e08cfaf28511b3bd5689f72fff1
diff --git a/y2019/control_loops/drivetrain/BUILD b/y2019/control_loops/drivetrain/BUILD
index 2e16e1d..9b9ba30 100644
--- a/y2019/control_loops/drivetrain/BUILD
+++ b/y2019/control_loops/drivetrain/BUILD
@@ -180,7 +180,7 @@
     srcs = ["target_selector_test.cc"],
     deps = [
         ":target_selector",
-        "//aos/events:shm-event-loop",
+        "//aos/events:simulated_event_loop",
         "//aos/testing:googletest",
         "//aos/testing:test_shm",
     ],
@@ -210,6 +210,7 @@
             "arm": [],
         }),
     linkstatic = True,
+    shard_count = 5,
     deps = [
         ":localizer",
         ":drivetrain_base",