Orphaning rubygem-heroku{,-api}

[Vít Ondruch]

Hi,

I am orphaning rubygem-heroku{,-api} since I was never really user of
these. Moreover, there packages are deprecated already and Heroku is
going to sunset the Heroku v2 API as well as these packages on April 15,
2017 [1].

Vít

[1] https://devcenter.heroku.com/changelog-items/862