Update basics-of-authentication.md

Deleted an extra </a> in the views/index.erb sample, line 68

Author: JeffSchering

content/guides/basics-of-authentication.md

@@ -65,7 +65,7 @@ Next, in _views/index.erb_, paste this content:
     </p>
     <p>
       We're going to now talk to the GitHub API. Ready?
-      <a href="https://github.com/login/oauth/authorize?scope=user:email&client_id=<%=%20client_id%20%>">Click here</a> to begin!</a>
+      <a href="https://github.com/login/oauth/authorize?scope=user:email&client_id=<%=%20client_id%20%>">Click here</a> to begin!
     </p>
     <p>
       If that link doesn't work, remember to provide your own <a href="/v3/oauth/#web-application-flow">Client ID</a>!