Merge pull request #138 from cs50/valgrind

Wording tweak for valgrind

Author: dmalan

check50.py

@@ -834,7 +834,7 @@ def _check_valgrind(self):
 
         # Only raise exception if we encountered errors.
         if reported:
-            raise Error("valgrind tests failed; rerun with --log for more information.")
+            raise Error("valgrind tests failed; rerun check50 with --log added to end of command for more information.")
 
 
 class Mismatch(object):