GitHub: only want the squash button; not merge (#30)

diff --git a/.asf.yaml b/.asf.yaml
index 9b75975..794f42d 100644
--- a/.asf.yaml
+++ b/.asf.yaml
@@ -10,3 +10,7 @@
     - lucene
     - website
     - pelican
+  enabled_merge_buttons:
+    squash: true
+    merge:  false
+    rebase: false
\ No newline at end of file