Add .iml files to .gitignore

Change-Id: I9e7cc39f77a027bb90bf41d32149e228d1dc04f4
diff --git a/.gitignore b/.gitignore
index 8cb536c..8bc2e12 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 .project
 .settings
 *.swp
+*.iml