bump libbson to 1.3.6

ajdavis · ajdavis · commit b6c4ecbaf77b · 2016-10-18T18:38:07.000-04:00
diff --git a/src/libbson b/src/libbson
@@ -1 +1 @@
-Subproject commit 1a0f35a2348ad677ae2fb10d7fc6e65c1a96322e
+Subproject commit 299bb833e6ac60e714f827302dd4c49d6e5e2f80
