Add Continuous Integration and LuaCheck (#2)

All warnings have been fixed as well. You can verify all is fine by checking the workflow run.

.github/workflows/build.yml

@@ -0,0 +1,11 @@
+on: [push, pull_request]
+name: build
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: lint
+        uses: Roang-zero1/factorio-mod-luacheck@master
+        with:
+          luacheckrc_url: ""

.luacheckrc

@@ -0,0 +1,12 @@
+unused_args = false
+allow_defined_top = true
+max_line_length = 999
+
+globals = {
+    "minetest", "ts_workshop",
+}
+
+read_globals = {
+    string = {fields = {"split", "trim"}},
+    table = {fields = {"copy", "getn"}},
+}

init.lua

@@ -84,8 +84,8 @@ function ts_workshop.register_workshop(mod, name, def)
 			local timer = minetest.get_node_timer(pos)
 			timer:start(0.2)
 		else
-			meta:set_int("progress", 0)
 			progress = 0
+			meta:set_int("progress", progress)
 			local inv = meta:get_inventory()
 			inv:add_item("output", working_on)
 			meta:set_string("working_on", "")