[jsk_topic_tools] Do not implement updateDiagnostic
as pure virtual method
Merge remote-tracking branch 'refs/remotes/origin/master' into garaemon-do-not-use-virtual-method-for-diagnostic-nodelet
Merge pull request #646 from garaemon/do-not-use-virtual-method-for-diagnostic-nodelet

[jsk_topic_tools] Do not implement updateDiagnostic as pure virtual method