switched to webhook to trigger rebuild, since tildegit's drone is broke

.drone.yml

@@ -1,8 +0,0 @@
-kind: pipeline
-type: exec
-name: rebuild site
-
-steps:
-- name: say hi
-  commands:
-  - echo "hello!"

dist/webhook-test.cgi

@@ -0,0 +1,7 @@
+#!/bin/sh
+printf "Content-Type: text/plain\r\n\r\n"
+#env
+if [ "$CONTENT_TYPE"="application/json" ] && [ "$HTTP_X_GITEA_EVENT"="push" ];then
+	echo "rebuilding"
+	"../build.sh"
+fi