Prepare for 0.21.1 release.

PiperOrigin-RevId: 305887195

Author: andylou2

RELEASE.md

@@ -10,6 +10,21 @@
 
 ### Deprecations
 
+## Release 0.21.1
+
+### Major Features and Improvements
+
+*   Bumped Tensorflow version for statically linked libraries from 1.5 to 2.1.
+
+### Bug Fixes and Other Changes
+
+*   Added tests for statically linked libraries.
+*   Statically linked libraries build now.
+
+### Breaking Changes
+
+### Deprecations
+
 ## Release 0.21.0
 
 ### Major Features and Improvements

struct2tensor/version.py

@@ -15,4 +15,4 @@
 """Contains the version string of struct2tensor."""
 
 # Note that setup.py uses this version.
-__version__ = '0.22.0dev'
+__version__ = '0.21.1'