feature/"Archive of Contemporary Composers' Websites"

@barnabyalter this pull request implements the "Archive of Contemporary Composers' Websites" collection which finishes user story [#67578010](https://www.pivotaltracker.com/story/show/67578010)

Highlights:
* Define ```Ichabod::ResourceSet::SourceReaders::ArchiveItAccw```, with specs, and vcr cassette
* Add "Archive of Contemporary Composers' Websites" ```Collection``` matcher, with spec
* Add ```ArchiveItAccw``` resource set with specs
* Add capistrano deploy tasks for loading/deleting collection data
* Add collection data loading step to Cucumber ```features/support/env.rb``` 

[Finishes #67578010]