Remove ap_url from mention (#362)

migrations/sqlite/2018-12-17-180104_mention_no_ap_url/down.sql

@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+ALTER TABLE mentions ADD COLUMN ap_url VARCHAR NOT NULL DEFAULT '';

migrations/sqlite/2018-12-17-180104_mention_no_ap_url/up.sql

@@ -0,0 +1,11 @@
+-- Your SQL goes here
+CREATE TABLE mentions2 (
+    id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+    mentioned_id INTEGER REFERENCES users(id) ON DELETE CASCADE NOT NULL,
+    post_id INTEGER REFERENCES posts(id) ON DELETE CASCADE,
+    comment_id INTEGER REFERENCES comments(id) ON DELETE CASCADE
+);
+
+INSERT INTO mentions2 SELECT id,mentioned_id,post_id,comment_id FROM mentions;
+DROP TABLE mentions;
+ALTER TABLE mentions2 RENAME TO mentions;