add mongoose submodule

[matrix_esp_thesis] / ext / mongoose

diff --git a/ext/mongoose b/ext/mongoose
new file mode 160000 (submodule)
index 0000000..45e4b3c
--- /dev/null
+++ b/ext/mongoose
@@ -0,0 +1 @@
+Subproject commit 45e4b3c423c7ee0f378b1b8682eccc533bed3f0d