Bump version to 0.7.2 for new release.

PiperOrigin-RevId: 435665900

Author: fredrec

tensorflow_model_optimization/python/core/version.py

@@ -17,7 +17,7 @@
 # We follow Semantic Versioning (https://semver.org/)
 _MAJOR_VERSION = '0'
 _MINOR_VERSION = '7'
-_PATCH_VERSION = '1'
+_PATCH_VERSION = '2'
 
 # When building releases, we can update this value on the release branch to
 # reflect the current release candidate ('rc0', 'rc1') or, finally, the official