add support for chalk/stderr (closes #301)

test/_supports-color.js

@@ -7,6 +7,12 @@ const DEFAULT = {
 		hasBasic: true,
 		has256: true,
 		has16m: true
+	},
+	stderr: {
+		level: 2,
+		hasBasic: true,
+		has256: true,
+		has16m: false
 	}
 };
 

test/stderr.js

@@ -0,0 +1,19 @@
+import test from 'ava';
+
+// Spoof supports-color
+require('./_supports-color')(__dirname);
+
+const chalk = require('../source');
+const chalkStderr = require('../stderr');
+
+test('import chalk/stderr with supports-color information for fd2', t => {
+	t.is(chalk.level, 3);
+	t.is(chalkStderr.level, 2);
+	t.is(chalkStderr.red('foo'), '\u001B[31mfoo\u001B[39m');
+});
+
+test('create isolated instance of stderr chalk', t => {
+	const instance = new chalkStderr.Instance();
+	t.is(instance.level, 2);
+	t.is(instance.red('foo'), '\u001B[31mfoo\u001B[39m');
+});