Ignoring vi swap file

Change-Id: I36dc970f9c6e8906550afa512a3b130a5edf2c2f
diff --git a/.gitignore b/.gitignore
index efff6da..9cfedb7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@
 /local.properties
 *.pyc
 /gwt-unitCache
+*.swp