Automate notification of new releases for closure-compiler

[knowtheory]

Closure-compiler has been github for a while and also uses Github to drop releases. Need to set up some basic scripts that could be run via cron to notify (and build if we can get that far) that the gem needs to be updated.

[YurySolovyov]

Notify who/how?

[knowtheory]

I'd be happy if we had something that created an issue here that said "TIME TO UPDATE THE GEM"

[YurySolovyov]

I guess that will require having some server+app to be able to subscribe to pushes and post issues here

[YurySolovyov]

I know it is not automated, but v20170626 is out