really basic test runner

npm test now does... something somewhat useful.

now to write a bunch of tests.

xmeffects.js

@@ -8,7 +8,7 @@ function eff_t1_0(ch) {  // arpeggio
   if (ch.effectdata != 0 && ch.inst != undefined) {
     var arpeggio = [0, ch.effectdata>>4, ch.effectdata&15];
     var note = ch.note + arpeggio[player.cur_tick % 3];
-    ch.period = player.PeriodForNote(ch, note);
+    ch.period = player.periodForNote(ch, note);
   }
 }
 
@@ -294,4 +294,4 @@ player.effects_t1 = [  // effect functions on tick 1+
   eff_unimplemented   // z
 ];
 
-})(window || {});
+})(window);