update latex presets

presets/presentations.tex

@@ -18,8 +18,10 @@
 \usepackage{color}
 \usepackage{proof}
 
+%%% source code
 \usepackage{listings}
 \usepackage{minted}
+\definecolor{bg}{rgb}{0.95, 0.95, 1.0}
 
 % page numbers in the bottom right
 \addtobeamertemplate{navigation symbols}{}{%
@@ -28,6 +30,3 @@
     \hspace{1em}%
     \raisebox{2pt}[0pt][0pt]{\insertframenumber/\inserttotalframenumber}
 }
-
-% code blocks
-