Merge pull request #504 from broadinstitute/jg/release_v0.6.4

Change the setup.py version 0.6.3 -> 0.6.4 for 0.6.4 release

Author: jkgoodrich

setup.py

@@ -15,7 +15,7 @@
 
 setuptools.setup(
     name="gnomad",
-    version="0.6.3",
+    version="0.6.4",
     author="The Genome Aggregation Database",
     author_email="[email protected]",
     description="Hail utilities for the Genome Aggregation Database",