Ignore Vim swap files in git-status output

Signed-off-by: martin f. krafft <madduck@madduck.net>
diff --git a/.gitignore b/.gitignore
index 0d3807b..93f9fe4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 *.pyc
+.*.sw?
 /reclass-config.yml
 /reclass.py