Add LUA linting

.drone.yml

@@ -16,7 +16,8 @@ steps:
   image: alpine
   commands:
     - apk update
-    - apk add --no-cache curl lua5.1 lua5.1-dev luarocks5.1
+    - apk add --no-cache build-base curl unzip
+    - apk add --no-cache lua5.1 lua5.1-dev luarocks5.1
     - luarocks-5.1 install --verbose luacheck
     - luacheck sources