Bumped version to 0.4.0.

Author: Parkayun

setup.py

@@ -8,7 +8,7 @@
 
 setup(
     name="bson",
-    version="0.3.5",
+    version="0.4.0",
     packages=["bson"],
     install_requires=["pytz>=2010b", "six>=1.9.0"],
     author="Ayun Park",