[rakefile] small tool to set release dates on changelogs. (#465)
[rakefile] small tool to set release dates on changelogs. (#465)

* [rakefile] small tool to set release dates on changelogs.

* [rakefile] fixing rubocop issues.

varlib1/servermall,DataDog/integrations-core,itsuugo/integrations-core,s-maj/integrations-core,s-maj/integrations-core,serverdensity/sd-agent-core-plugins,serverdensity/sd-agent-core-plugins,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,s-maj/integrations-core,varlib1/servermall,varlib1/servermall,DataDog/integrations-core,DataDog/integrations-core,itsuugo/integrations-core,StackVista/sts-agent-integrations-core,DataDog/integrations-core,StackVista/sts-agent-integrations-core,s-maj/integrations-core,s-maj/integrations-core,varlib1/servermall,itsuugo/integrations-core,StackVista/sts-agent-integrations-core,DataDog/integrations-core,itsuugo/integrations-core,itsuugo/integrations-core,serverdensity/sd-agent-core-plugins,StackVista/sts-agent-integrations-core,DataDog/integrations-core,StackVista/sts-agent-integrations-core,serverdensity/sd-agent-core-plugins,serverdensity/sd-agent-core-plugins,DataDog/integrations-core,varlib1/servermall