Copy Resources, Delete Transformations

NEW FEATURES:

• resources copy <resource> <new_resource> with optional flag --deep to also associate new resource Transformations with Element; addresses #16
• transformations delete <resource> <element>, to delete a Transformation association from an Element, which is a prerequisite if deleting a Resource (existing capability in resources delete <resource>
• incomplete transformations associate <resource> <element> as there's still more discussion (#20)

BUG FIXES:

IMPROVEMENTS:

• copyright statement added to transformations.go source file
• deleting an resource would continue even if it resulted in a non-200 response, resulting in a confusing output