Prepare for struct2tensor 0.22.0 release.

PiperOrigin-RevId: 311551437

Author: andylou2

RELEASE.md

@@ -1,11 +1,13 @@
 # `struct2tensor` release notes
 
-## Current Version(Still in Development)
+## Release 0.22.0
 
 ### Major Features and Improvements
 
 ### Bug Fixes and Other Changes
 
+*   Depends on `tensorflow>=2.2.0,<2.3
+
 ### Breaking Changes
 
 ### Deprecations

setup.py

@@ -62,7 +62,7 @@ def has_ext_modules(self):
     packages=find_packages(),
     install_requires=[
         'protobuf>=3.8.0,<4',
-        'tensorflow>=2.1.0,<2.2',
+        'tensorflow>=2.2.0,<2.3',
         'tensorflow_metadata>=0.21,<0.22',
         'pyarrow>=0.15,<1',
     ],

struct2tensor/version.py

@@ -15,4 +15,4 @@
 """Contains the version string of struct2tensor."""
 
 # Note that setup.py uses this version.
-__version__ = '0.22.0.dev'
+__version__ = '0.22.0'