Better version check on push

(cherry picked from commit d5536abdb51d949d506a7c3202cb05326b12cb97)
Script to help mark new versions

(cherry picked from commit 35313c605c144baa362f1523ee6a780fde54621f)
Kubernetes version v0.5.3
Kubernetes version v0.5.3-dev
Merge pull request #2577 from jbeda/release-0.5

Release v0.5.3