update heroku deployment to reflect dependency changes

[bengolder]

Now that this no longer depends on pdftk, the heroku and govcloud deployment configuration should be updated. If someone tried to deploy this in its current state, it might break.

[brennv]

Does the govcloud config refer to cloudfoundry?

Also can we add this service? https://requires.io/

[bengolder]

Yes, I thing govcloud is a specific running version of cloudfoundry.

[bengolder]

And requires.io looks great! Yes!