Add LUA linting

.drone.yml

@@ -16,7 +16,7 @@ steps:
   image: alpine
   commands:
     - apk update
-    - RUN apk add --no-cache lua lua-dev luarocks
+    - apk add --no-cache lua lua-dev luarocks
     - which luarocks
     - luarocks install luacheck
     - luacheck sources