Update .gitignore

.gitignore

diff --git a/.gitignore b/.gitignore
index f1e3d20..f7b4a8b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,9 @@
 ## Ignore Visual Studio temporary files, build results, and
 ## files generated by popular Visual Studio add-ons.
 
+# Ignore mercurial metadata dirs
+.hg
+
 # User-specific files
 *.suo
 *.user