add post log api

lib/db/log.js

@@ -18,5 +18,10 @@ module.exports = (get_db) => ({
     )
       .from ('log')
       .where ({ app_id });
+  },
+  insert (app_id, message, data = '{}', timestamp = (new Date)) {
+    const knex = get_db ();
+    return knex ('log')
+      .insert ({ message, data, timestamp, app_id });
   }
 });