Add GitHub workflow and luacheck (#545)

Add badge to README
Fix luacheck warnings
Remove node_ownership globals (and support)

technic/machines/LV/geothermal.lua

@@ -27,7 +27,7 @@ minetest.register_craftitem("technic:geothermal", {
 local check_node_around = function(pos)
 	local node = minetest.get_node(pos)
 	if node.name == "default:water_source" or node.name == "default:water_flowing" then return 1 end
-	if node.name == "default:lava_source"  or node.name == "default:lava_flowing"  then return 2 end	
+	if node.name == "default:lava_source"  or node.name == "default:lava_flowing"  then return 2 end
 	return 0
 end
 

technic/machines/LV/music_player.lua

@@ -24,7 +24,6 @@ local run = function(pos, node)
 	local meta         = minetest.get_meta(pos)
 	local eu_input     = meta:get_int("LV_EU_input")
 	local machine_name = S("%s Music Player"):format("LV")
-	local machine_node = "technic:music_player"
 	local demand       = 150
 
 	local current_track = meta:get_int("current_track")

technic/machines/LV/solar_panel.lua

@@ -51,7 +51,7 @@ minetest.register_node("technic:solar_panel", {
 		technic_machine=1, technic_lv=1},
 	connect_sides = {"bottom"},
 	sounds = default.node_sound_wood_defaults(),
-    	description = S("Small Solar %s Generator"):format("LV"),
+	description = S("Small Solar %s Generator"):format("LV"),
 	active = false,
 	drawtype = "nodebox",
 	paramtype = "light",

technic/machines/LV/water_mill.lua

@@ -29,8 +29,8 @@ end
 local run = function(pos, node)
 	local meta             = minetest.get_meta(pos)
 	local water_flow       = 0
-	local production_level = 0
-	local eu_supply        = 0
+	local production_level
+	local eu_supply
 	local max_output       = 4 * 45 -- keeping it around 180, little more than previous 150 :)
 
 	local positions = {