Move 2018 arm code to frc971 and make dynamics adjustable

Signed-off-by: Maxwell Henderson <mxwhenderson@gmail.com>
Change-Id: I16e7bbb0d293aca461abc931f560fb9066b19aaf
diff --git a/y2018/BUILD b/y2018/BUILD
index ac59493..8feaac4 100644
--- a/y2018/BUILD
+++ b/y2018/BUILD
@@ -57,9 +57,10 @@
         "//aos/network:team_number",
         "//aos/stl_mutex",
         "//frc971:constants",
+        "//frc971/control_loops/double_jointed_arm:dynamics",
         "//frc971/shooter_interpolation:interpolation",
         "//y2018/control_loops/drivetrain:polydrivetrain_plants",
-        "//y2018/control_loops/superstructure/arm:dynamics",
+        "//y2018/control_loops/superstructure/arm:arm_constants",
         "//y2018/control_loops/superstructure/intake:intake_plants",
         "@com_github_google_glog//:glog",
     ],