Increments version to 0.6.4

Author: halfak

revscoring/__init__.py

@@ -51,4 +51,4 @@
 
     Example: *TODO*
 """
-__version__ = "0.6.3"
+__version__ = "0.6.4"

setup.py

@@ -13,7 +13,7 @@ def requirements(fname):
 
 setup(
     name="revscoring",
-    version="0.6.3", # change in revscoring/__init__.py
+    version="0.6.4", # change in revscoring/__init__.py
     author="Aaron Halfaker",
     author_email="ahalfaker@wikimedia.org",
     description=("A set of utilities for generating quality scores for " + \