Fix typo in previous commit, add associated test

Author: danburzo

docs/api.md

@@ -730,7 +730,7 @@ let names = Object.keys(palette);
 let nearestColors = culori.nearest(
 	names,
 	culori.differenceEuclidean(),
-	name => colors[name]
+	name => palette[name]
 );
 
 nearestColors('red', 1);

test/nearest.test.js

@@ -28,3 +28,17 @@ tape('check against named colors', test => {
 
 	test.end();
 });
+
+tape('nearest() with accessor', t => {
+	let palette = {
+		Burgundy: '#914e72',
+		Blue: '#0078bf',
+		Green: '#00a95c',
+		'Medium Blue': '#3255a4',
+		'Bright Red': '#f15060'
+	};
+	let names = Object.keys(palette);
+	let nearestColors = nearest(names, undefined, name => palette[name]);
+	t.deepEqual(nearestColors('red', 1), ['Bright Red']);
+	t.end();
+});