Update gitignore

Ignoring IntelliJ files.

Change-Id: I4c080dc79f737d23ac258f3b119524a360d57ff2
diff --git a/.gitignore b/.gitignore
index d392f0e..a9fe73b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 *.jar
+.idea
+*.iml