Bump up stable version to 0.3.1.

PiperOrigin-RevId: 373300584

Author: lintian06

tensorflow_examples/lite/model_maker/RELEASE.md

@@ -2,7 +2,8 @@
 
 ## 0.3.1
 
-*   Polish document with minor changes.
+*   Polish document showing in
+    https://www.tensorflow.org/lite/api_docs/python/tflite_model_maker.
 *   Add some 0.2.x APIs for backward compatibility.
 
 ## 0.3.0

tensorflow_examples/lite/model_maker/pip_package/setup.py

@@ -57,14 +57,14 @@
 # Set package version.
 if nightly:
   project_name = '{}-nightly'.format(project_name)
-  version = '0.3.1'  # Version prefix, usually major.minor.micro.
+  version = '0.3.2'  # Version prefix, usually major.minor.micro.
   version = '{:s}.dev{:s}'.format(version, datestring)
   classifiers += [
       'Development Status :: 4 - Beta',
   ]
 else:
   # LINT.IfChange(model_maker_pip_version)
-  version = '0.3.0'
+  version = '0.3.1'
   # LINT.ThenChange(../public/__init__.py, ../RELEASE.md)
 
 # Path to model_maker dir: <repo>/tensorflow_examples/lite/model_maker