Support http-basic-auth via basicAuth setting

use settings.basicAuth.username and settings.basicAuth.password to
configure basic authentication.

Author: staabm

lib/wordpress.js

@@ -44,7 +44,11 @@ function Client( settings ) {
 		// via settings.host
 		headers: {
 			Host: parsedUrl.host
-		}
+		},
+		basic_auth: settings.basicAuth ? {
+			user: settings.basicAuth.username,
+			pass: settings.basicAuth.password
+		} : null,
 	});
 	this.blogId = settings.blogId || 0;
 	this.username = settings.username;