Bump version to 2.2 (#81)

Author: tetron

setup.py

@@ -47,7 +47,7 @@
 extras_require = {}               # TODO: to be removed when the above is added
 
 setup(name='schema-salad',
-      version='2.1',
+      version='2.2',
       description='Schema Annotations for Linked Avro Data (SALAD)',
       long_description=open(README).read(),
       author='Common workflow language working group',