Revert "Merge branch 'remove-dummy-output-pin' into century-error"

This reverts commit a9b15528c2, reversing
changes made to e087909f0b.

tests/common/mod.rs

@@ -57,6 +57,21 @@ impl BitFlags {
     pub const WEEKDAY: u8 = 0b0100_0000;
 }
 
+pub struct DummyOutputPin;
+
+impl embedded_hal::digital::OutputPin for DummyOutputPin {
+    fn set_low(&mut self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+    fn set_high(&mut self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+impl embedded_hal::digital::ErrorType for DummyOutputPin {
+    type Error = embedded_hal::digital::ErrorKind;
+}
+
 pub fn new_ds3231(
     transactions: &[I2cTrans],
 ) -> Ds323x<interface::I2cInterface<I2cMock>, ic::DS3231> {