[maven-release-plugin] prepare release zendesk-java-client-0.5.2
[maven-release-plugin] prepare release zendesk-java-client-0.5.2

norrisjeremy/zendesk-java-client,gvh1234/zendesk-java-client,matthewtckr/zendesk-java-client,cloudbees/zendesk-java-client,christ66/zendesk-java-client