feat: robot instances can be created with a given initial state

robot.lua

@@ -2,14 +2,18 @@
 
 local api = {}
 
-api.create = function()
-  local state = {
+local function createDefaultState()
+  return {
     y = 0,
     x = 0,
     z = 0,
     -- | BACKWARD | LEFT | RIGHT
     dir = 'FORWARD'
   }
+end
+
+api.create = function(state)
+  state = state or createDefaultState()
 
   local mutateRobotPosition = function(isBackward)
     local incValue = 1