Add licenses() to all BUILD files. (#141)

docs/BUILD

diff --git a/docs/BUILD b/docs/BUILD
index f4f6b55..7bf427b 100644
--- a/docs/BUILD
+++ b/docs/BUILD
@@ -1,5 +1,7 @@
 load("@io_bazel_skydoc//stardoc:stardoc.bzl", "stardoc")
 
+licenses(["notice"])
+
 # Note that due to a bug in Bazel 0.22.0, these targets cannot be built without
 # the --incompatible_remap_main_repo flag.
 stardoc(

rules/private/BUILD

diff --git a/rules/private/BUILD b/rules/private/BUILD
index df4dced..63d76d8 100644
--- a/rules/private/BUILD
+++ b/rules/private/BUILD
@@ -1,5 +1,7 @@
 load("//:bzl_library.bzl", "bzl_library")
 
+licenses(["notice"])
+
 bzl_library(
     name = "copy_file_private",
     srcs = ["copy_file_private.bzl"],

tests/copy_file/BUILD

diff --git a/tests/copy_file/BUILD b/tests/copy_file/BUILD
index 47d7887..7c8a4c3 100644
--- a/tests/copy_file/BUILD
+++ b/tests/copy_file/BUILD
@@ -33,6 +33,8 @@
 
 load("//rules:copy_file.bzl", "copy_file")
 
+licenses(["notice"])
+
 package(default_testonly = 1)
 
 sh_test(

tests/diff_test/BUILD

diff --git a/tests/diff_test/BUILD b/tests/diff_test/BUILD
index 3a33bf2..bd0aacd 100644
--- a/tests/diff_test/BUILD
+++ b/tests/diff_test/BUILD
@@ -2,6 +2,8 @@
 
 load("//rules:diff_test.bzl", "diff_test")
 
+licenses(["notice"])
+
 package(default_testonly = 1)
 
 sh_test(

tests/maprule/BUILD

diff --git a/tests/maprule/BUILD b/tests/maprule/BUILD
index 390b96d..5f69c68 100644
--- a/tests/maprule/BUILD
+++ b/tests/maprule/BUILD
@@ -5,6 +5,8 @@
 
 load("//rules/private:maprule.bzl", "bash_maprule")
 
+licenses(["notice"])
+
 package(default_testonly = 1)
 
 sh_test(

tests/write_file/BUILD

diff --git a/tests/write_file/BUILD b/tests/write_file/BUILD
index 52d7992..321bcc0 100644
--- a/tests/write_file/BUILD
+++ b/tests/write_file/BUILD
@@ -34,6 +34,8 @@
 
 load("//rules:write_file.bzl", "write_file")
 
+licenses(["notice"])
+
 package(default_testonly = 1)
 
 sh_test(