Update tests with basic init

src/apu.rs

@@ -91,6 +91,10 @@ impl APU {
                 self.pulse_2.enabled = val & 0b0000_0010 != 0;
                 self.pulse_1.enabled = val & 0b0000_0001 != 0;
             }
+            0x10 => {
+                assert_eq!(val, 0x00);
+                // TODO: implement this value
+            }
             0x11 => {
                 // TODO: load dmc counter with (val & 7F)
             }