Feature/resource set

@barnabyalter I need to make the rake tasks work, but figured I'd open the PR to get some feedback/start a conversation sooner than later.

@NYULibraries/hydra please have a look and provide feedback as you see fit.
@scotdalton I know this is from a previous pull and I'm sure I missed it, but since you're changing this feature anyway it should really be

`Given I change...`
`Given I revert...`

Where the step is

`Given(/^I (change|revert) the...$/)`