Add basic python rule for flatbuffers

Not 100% sure I'm actually going to *use* this now that I've looked at
things more carefully, but it may be helpful for doing some data
analysis stuff.

Change-Id: I695cfe019639617da5baec4d45f5de71ad79b223
diff --git a/third_party/flatbuffers/BUILD b/third_party/flatbuffers/BUILD
index 67a3a14..492f158 100644
--- a/third_party/flatbuffers/BUILD
+++ b/third_party/flatbuffers/BUILD
@@ -231,3 +231,9 @@
         "--cpp-ptr-type flatbuffers::unique_ptr",
     ],
 )
+
+py_library(
+    name = "flatpy",
+    srcs = glob(["python/flatbuffers/*.py"]),
+    imports = ["python/"],
+)