updating tools for figure conversion

tools/update_figures.py

+#!/usr/bin/python3
+from sys import argv
+from os import system 
+
+if len(argv)<2: 
+    print("usage:\npython3 update_figures.py NAME")
+else:
+    system("pdftoppm {fig}.pdf {fig} -png -cropbox".format(fig=argv[1]))
+    system("mv {fig}-1.png {fig}.png".format(fig=argv[1]))
+    system("rm {fig}.pdf".format(fig=argv[1]))
+