Ignore IntelliJ *.iml files

Change-Id: Ib0386f5453ae472cd703d5257fcd163d821f2d2c
diff --git a/.gitignore b/.gitignore
index 47617be..1e10b15 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@
 /.buckd
 /buck-cache
 /buck-out
+*.iml