Bump release version to 2.3.0
Bump release version to 2.3.0

[#105725754]

Signed-off-by: Leo Chu <a4dab1a96fe3d3ca42abb90f3212fe8a512a2bf1@gmail.com>

cloudfoundry-incubator/routing-api-cli,cloudfoundry-incubator/routing-api-cli