Remove autoSkip logic to always display last tick

This changes the behavior of `autoSkip` so that it does not force the
display of the last tick. If the last tick can be displayed with equal
spacing to the rest of the ticks, it will be. Otherwise, it is not.

src/core/core.scale.js

@@ -669,9 +669,8 @@ module.exports = Element.extend({
 		for (i = 0; i < tickCount; i++) {
 			tick = ticks[i];
 
-			// Since we always show the last tick,we need may need to hide the last shown one before
-			shouldSkip = (skipRatio > 1 && i % skipRatio > 0) || (i % skipRatio === 0 && i + skipRatio >= tickCount);
-			if (shouldSkip && i !== tickCount - 1) {
+			shouldSkip = (skipRatio > 1 && i % skipRatio > 0);
+			if (shouldSkip) {
 				// leave tick in place but make sure it's not displayed (#4635)
 				delete tick.label;
 			}