elqr works for the arm, no constraints.

Another prototype of an MPC.  This one doesn't work with constraints,
but solves quickly to an optimal solution.

Change-Id: I388a784cbd515874aeb89fafedb1de5f137e60db
diff --git a/y2018/control_loops/python/BUILD b/y2018/control_loops/python/BUILD
index 369dc96..14118a3 100644
--- a/y2018/control_loops/python/BUILD
+++ b/y2018/control_loops/python/BUILD
@@ -195,3 +195,16 @@
     visibility = ["//visibility:public"],
     deps = ["//y2018/control_loops:python_init"],
 )
+
+py_binary(
+    name = "extended_lqr",
+    srcs = [
+        "extended_lqr.py",
+    ],
+    restricted_to = ["//tools:k8"],
+    deps = [
+        "//external:python-gflags",
+        "//external:python-glog",
+        "//frc971/control_loops/python:controls",
+    ],
+)