Added exercise to balance slides

slides/content/balance.tex

@@ -168,7 +168,16 @@
 		\end{itemize}
 	\end{frame}
 
-	
+	\begin{frame}{Exercise}
+		\begin{block}{Exercise}
+			Investigate dominant strategy in Civ style game
+		\end{block}
+		\begin{itemize}
+			\item Download latest copy of the \href{https://git.fossgalaxy.com/ce810/module-game}{game engine}
+			\item Look at and run class ``DominantStrategy''
+			\item Create new maps that don't display this behaviour
+		\end{itemize}
+	\end{frame}	
 	
 	\section{Watching}
 	\begin{frame}{Extra Credits}