reverse the Instructions vector, so he can behave as a queue

src/main.rs

@@ -172,7 +172,7 @@ fn parse_config(conf: String, pool: &mut Vec<robot::Robot>) -> Result<world::Wor
         };
 
         // Convert instructions line.
-        let inst: Vec<char> = raw_inst.chars().collect();
+        let inst: Vec<char> = raw_inst.chars().rev().collect();
         if !robot::is_instructions(&inst) {
             return Err(String::from("Invalid instructions !"));
         }