remove move left/right

src/main.rs

@@ -109,26 +109,6 @@ impl Robot {
             Orientation::W => self.p.x -= 1,
         }
     }
-    /// Apply right instruction to the robot.
-    fn move_right(&mut self, w: &mut World) {
-        w.map[(self.p.x + (self.p.y * w.x as i32)) as usize] = '.';
-        match self.o {
-            Orientation::N => self.p.x += 1,
-            Orientation::S => self.p.x -= 1,
-            Orientation::E => self.p.y += 1,
-            Orientation::W => self.p.y -= 1,
-        }
-    }
-    /// Apply left instruction to the robot.
-    fn move_left(&mut self, w: &mut World) {
-        w.map[(self.p.x + (self.p.y * w.x as i32)) as usize] = '.';
-        match self.o {
-            Orientation::N => self.p.x -= 1,
-            Orientation::S => self.p.x += 1,
-            Orientation::E => self.p.y -= 1,
-            Orientation::W => self.p.y += 1,
-        }
-    }
     /// Apply North orientation to the robot.
     fn set_north(&mut self) {
         self.o = Orientation::N