Bump TF version to 2.3.0rc2+ (#1048)
Bump TF version to 2.3.0rc2+ (#1048)

TF has released 2.3.0rc2, this PR bumps the version.

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>
tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io