Fix compiler error on Windows

setup.py

@@ -78,11 +78,13 @@ class BuildExt(build_ext):
     def build_extensions(self):
         ct = self.compiler.compiler_type
         opts = self.c_opts.get(ct, [])
-        opts.append('-DVERSION_INFO="%s"' % self.distribution.get_version())
         if ct == 'unix':
+            opts.append('-DVERSION_INFO="%s"' % self.distribution.get_version())
             opts.append(cpp_flag(self.compiler))
             if has_flag(self.compiler, '-fvisibility=hidden'):
                 opts.append('-fvisibility=hidden')
+        elif ct == 'msvc':
+            opts.append('/DVERSION_INFO=\\"%s\\"' % self.distribution.get_version())
         for ext in self.extensions:
             ext.extra_compile_args = opts
         build_ext.build_extensions(self)