Restrain public files to the public/ folder

As raised by Adriaan (@agboom), the .github-user-tokens.json file was
incorrectly exposed, causing the risk of users' GitHub tokens to be used
by other entities for the purpose of increasing their rate limits by
pretending to be shields.io.

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-    <img src="https://rawgit.com/badges/shields/master/logo.svg"
+    <img src="https://rawgit.com/badges/shields/master/public/logo.svg"
          height="130">
 </p>
 <p align="center">

public/favicon.png

@@ -0,0 +1 @@
+../favicon.png

public/index.html

@@ -0,0 +1 @@
+../index.html

public/try.html

@@ -0,0 +1 @@
+../try.html

server.js

@@ -3,9 +3,10 @@ var serverPort = +process.env.PORT || +process.argv[2] || (secureServer? 443: 80
 var bindAddress = process.env.BIND_ADDRESS || process.argv[3] || '::';
 var infoSite = process.env.INFOSITE || "http://shields.io";
 var githubApiUrl = process.env.GITHUB_URL || 'https://api.github.com';
+var path = require('path');
 var Camp = require('camp');
 var camp = Camp.start({
-  documentRoot: __dirname,
+  documentRoot: path.join(__dirname, 'public'),
   port: serverPort,
   hostname: bindAddress,
   secure: secureServer