update the version (#424)

Update the version for the new release.

Author: allieychen

setup.py

@@ -61,7 +61,7 @@ def run(self):
 
 setuptools.setup(
     name='gcp_variant_transforms',
-    version='0.5.0',
+    version='0.5.1',
     description=('Tool for transforming and processing VCF files in a '
                  'scalable manner based on Apache Beam'),
     author='Google',