use future testing for Buffer.from

`alloc` and `allocUnsafe` were backported with `from` and not used in Buffer class
https://github.com/LinusU/buffer-from/blob/master/index.js#L3

index.js

@@ -18,6 +18,12 @@ const nodeStatusCodes = require('node-status-codes');
 const isRetryAllowed = require('is-retry-allowed');
 const pkg = require('./package.json');
 
+const isModernBuffer = (
+	typeof Buffer.alloc === 'function' &&
+	typeof Buffer.allocUnsafe === 'function' &&
+	typeof Buffer.from === 'function'
+);
+
 function requestAsEventEmitter(opts) {
 	opts = opts || {};
 
@@ -40,8 +46,11 @@ function requestAsEventEmitter(opts) {
 					ee.emit('error', new got.MaxRedirectsError(statusCode, opts), null, res);
 					return;
 				}
-				const isNode4 = process.version ? process.version.indexOf('v4.') === 0 : true;
-				const bufferString = isNode4 ? new Buffer(res.headers.location, 'binary').toString() : Buffer.from(res.headers.location, 'binary').toString();
+
+				const bufferString = isModernBuffer ?
+					Buffer.from(res.headers.location, 'binary').toString() :
+					new Buffer(res.headers.location, 'binary').toString();
+
 				redirectUrl = urlLib.resolve(urlLib.format(opts), bufferString);
 				const redirectOpts = Object.assign({}, opts, urlLib.parse(redirectUrl));