Updated readme
Updated readme

- Updated installation instructions for clarity
- Removed base64 encoding from list of functionality
- Called out SpecHelperStubs as a separate section from SpecHelper
- Includes some examples

joemasilotti/PivotalCoreKit,pivotal/PivotalCoreKit,jfuchs/PivotalCoreKit,pivotaltracker/PivotalCoreKit,jfuchs/PivotalCoreKit,idoru/PivotalCoreKit,mjstallard/PivotalCoreKit,gudatcomputers/PivotalCoreKit,briancroom/PivotalCoreKit,gudatcomputers/PivotalCoreKit,idoru/PivotalCoreKit,joemasilotti/PivotalCoreKit