Perform basic turret auto-aiming

Implements a basic aimer which will shoot balls straight at the origin.

This still leaves a variety of things to be done:
-Actually shooting at the correct coordinates.
-Choosing between whether to shoot at the 2-point goal or 3-point goal.
-Managing turret wrap/redundancy intelligently.
-Shooting on the fly.

Change-Id: If4fc6249951faa5300411a0ca7d29da9e11dbb15
diff --git a/y2020/control_loops/superstructure/turret/BUILD b/y2020/control_loops/superstructure/turret/BUILD
index 894d418..8403e7c 100644
--- a/y2020/control_loops/superstructure/turret/BUILD
+++ b/y2020/control_loops/superstructure/turret/BUILD
@@ -30,3 +30,27 @@
         "//frc971/control_loops:state_feedback_loop",
     ],
 )
+
+cc_library(
+    name = "aiming",
+    srcs = ["aiming.cc"],
+    hdrs = ["aiming.h"],
+    deps = [
+        "//aos:flatbuffers",
+        "//frc971/control_loops:control_loops_fbs",
+        "//frc971/control_loops:pose",
+        "//frc971/control_loops:profiled_subsystem_fbs",
+        "//frc971/control_loops/drivetrain:drivetrain_status_fbs",
+        "//y2020/control_loops/drivetrain:drivetrain_base",
+        "//y2020/control_loops/superstructure:superstructure_status_fbs",
+    ],
+)
+
+cc_test(
+    name = "aiming_test",
+    srcs = ["aiming_test.cc"],
+    deps = [
+        ":aiming",
+        "//aos/testing:googletest",
+    ],
+)