Add questions page

presentation.tex

   \item{Exercism(not clojure specific) \url{http://exercism.io/}}
   \end{itemize}
 \end{frame}
+
+\section{Questions?}
+\begin{frame}
+  \begin{center}
+    \Huge Questions?
+  \end{center}
+\end{frame}
 \end{document}