Import buildifier

This patch sets up buildifier to run as part of CI. It can also be run
manually via `//tools/lint:buildifier`.

As a consequence, I needed to make the whole repo conform.

Signed-off-by: Philipp Schrader <philipp.schrader@gmail.com>
Change-Id: Ic41c97b17255813b6c21aef40ab2f8a216683a2c
diff --git a/y2020/control_loops/superstructure/BUILD b/y2020/control_loops/superstructure/BUILD
index e5ff8dc..74ccece 100644
--- a/y2020/control_loops/superstructure/BUILD
+++ b/y2020/control_loops/superstructure/BUILD
@@ -1,8 +1,8 @@
-package(default_visibility = ["//visibility:public"])
-
 load("@com_github_google_flatbuffers//:build_defs.bzl", "flatbuffer_cc_library", "flatbuffer_ts_library")
 load("@npm_bazel_typescript//:defs.bzl", "ts_library")
 
+package(default_visibility = ["//visibility:public"])
+
 flatbuffer_cc_library(
     name = "superstructure_goal_fbs",
     srcs = [