Add rules for packaging up Ruby code.

These were originally written by Parker and then cleaned up by me.

Change-Id: I93b66c83f80ca86a267abb84cab5f160b837083b
diff --git a/build_tests/BUILD b/build_tests/BUILD
index e11937b..75198fd 100644
--- a/build_tests/BUILD
+++ b/build_tests/BUILD
@@ -1,3 +1,5 @@
+load('/tools/build_rules/ruby', 'ruby_binary')
+
 cc_test(
   name = 'gflags_build_test',
   srcs = [
@@ -8,3 +10,25 @@
   ],
   size = 'small',
 )
+
+ruby_binary(
+  name = 'ruby_binary',
+  srcs = [
+    'ruby.rb',
+    'ruby_to_require.rb',
+  ],
+  data = [
+    'ruby_to_require.rb',
+  ],
+)
+
+sh_test(
+  name = 'ruby_build_test',
+  srcs = [
+    'ruby_check.sh',
+  ],
+  data = [
+    ':ruby_binary',
+  ],
+  size = 'small',
+)