Merge branch 'headers' of github.com:bazelbuild/bazel-skylib into headers

tests/diff_test/BUILD

diff --git a/tests/diff_test/BUILD b/tests/diff_test/BUILD
index afed401..1fd1d91 100644
--- a/tests/diff_test/BUILD
+++ b/tests/diff_test/BUILD
@@ -14,6 +14,7 @@
         "//tests:unittest.bash",
     ],
     deps = ["@bazel_tools//tools/bash/runfiles"],
+    # Test marked local because it uses bazel.
     tags = ["local"],
 )