feat(auth): implement user authentication system

backend/node_modules/cookie-signature/Readme.md

@@ -0,0 +1,23 @@
+
+# cookie-signature
+
+  Sign and unsign cookies.
+
+## Example
+
+```js
+var cookie = require('cookie-signature');
+
+var val = cookie.sign('hello', 'tobiiscool');
+val.should.equal('hello.DGDUkGlIkCzPz+C0B064FNgHdEjox7ch8tOBGslZ5QI');
+
+var val = cookie.sign('hello', 'tobiiscool');
+cookie.unsign(val, 'tobiiscool').should.equal('hello');
+cookie.unsign(val, 'luna').should.be.false;
+```
+
+## License
+
+MIT.
+
+See LICENSE file for details.