removed mdash characters from setup.py

setup.py

@@ -57,8 +57,8 @@ Boost.Python by David Abrahams: to minimize boilerplate code in traditional
 extension modules by inferring type information using compile-time
 introspection.
 
-The main issue with Boost.Python—and the reason for creating such a similar
-project—is Boost. Boost is an enormously large and complex suite of utility
+The main issue with Boost.Python-and the reason for creating such a similar
+project-is Boost. Boost is an enormously large and complex suite of utility
 libraries that works with almost every C++ compiler in existence. This
 compatibility has its cost: arcane template tricks and workarounds are
 necessary to support the oldest and buggiest of compiler specimens. Now that