Move migrate to abra.sh command

abra.sh

@@ -1,5 +1,11 @@
 export APP_ENTRYPOINT_VERSION=v4
 
+migrate() {
+	export DATABASE_PASSWORD=$(cat /run/secrets/db_password)
+	export DATABASE_URL="postgres://outline:${DATABASE_PASSWORD}@${STACK_NAME}_postgres:5432/outline"
+	yarn db:migrate --env=production-ssl-disabled
+}
+
 delete_user() {
 	if [ -z "$1" ] || [ -z "$2" ]; then
 		echo "Usage: ... delete_user <user-to-delete> <user-to-replace>"