Theoretically, fix random seed

But, practically and unfortunately, don't...

Theory was that, since OUTPUT_PIN makes its way
to GND/LOW eventually, it isn't floating enough
to provide different HIGH/LOW values. And that's
why, when using batteries but surprisingly not
when using the programmer for power, we always
seemed to get the same first interval sequence.

UP_PIN and DOWN_PIN seem better options, since
they float before the internal pull-downs are set
and assuming user isn't holding their buttons.

However, changing to UP_PIN yielded identical
behavior.

Not only that, but straight up using LOW did too.

So, IDK wussup, but theoretically-improved-but-
practically-identical is better enough in my book.
Committing with this lengthy message as proof of
effort.

Author: rocktronica

arduino/higher_lower/common.h

@@ -12,7 +12,7 @@
 #define CTRL_PIN 8
 #endif
 
-#define SEED_PIN OUTPUT_PIN
+#define SEED_PIN UP_PIN
 
 #define THEME_NOTE_LENGTH 180
 

arduino/higher_lower/higher_lower.ino

@@ -97,8 +97,10 @@ void reset() {
 }
 
 void setup() {
+  // NOTE: seed before setup, before input pins are pulled
   initRandomSeed();
   setupInterface();
+
   setupSerial();
   reset();
 }