Update ci to rubocop and add brakeman

.drone.yml

@@ -26,7 +26,17 @@ steps:
   - name: bundle
     path: /usr/local/bundle
   commands:
-  - bin/bundle exec standardrb
+  - bin/rubocop
+  depends_on:
+  - install
+
+- name: brakeman
+  image: ruby:3.3.1
+  volumes:
+  - name: bundle
+    path: /usr/local/bundle
+  commands:
+  - bin/brakeman
   depends_on:
   - install