Using VCR to fake out Stormpath API

- tests now delete Resources they've created

- tests use hard-coded names instead of relying on generate_resource_name

- if STORMPATH_SDK_TEST_ENVIRONMENT equals "CI" (only Travis should have this), all requests should go (all the time) to the Stormpath API, bypassing the VCR cassettes

- nuking the Bootstrapper + specs, - TODO: replace with a CLI