Bump to v0.6.0 [skip ci]

Author: kmkurn

setup.py

@@ -8,7 +8,7 @@
 
 
 setup(name='pytorch-crf',
-      version='0.5.1',
+      version='0.6.0',
       description='Conditional random field in PyTorch',
       long_description=readme,
       url='https://github.com/kmkurn/pytorch-crf',