Added TestFlightSDK via CocoaPods

Installed TestFlightSDK 1.2.
Integrated TestFlightSDK in project.

Added build configuration named "App Store" for use when archiving to
release to the App Store. This sets APPSTORE=1 which strips deprecated
code (UUID) used for TestFlightSDK analytics.
Added TestFlight.h to precompiled header.
Started TestFlight session immediately after launch. Requires
TestFlight App token before building!
Added TestFlightSDK to dependencies in README.md.
Added MYSSecretKey.h to Xcode project for storing API keys used by the app. Updated README.md.

Added MYSSecretKey.h to .gitignore so private keys are never commited
to the public repository.
Added MYSSecretKeys.example.h as template for MYSSecretKeys.h.
Added building instructions for MYSSecretKeys.h to README.md.
Removed LICENSE.md and README.md from Mycoscope target in Xcode project.
Removed Podfile from Mycoscope target in Xcode project. Updated .gitignore comments.
Imported MYSSecretKeys.h in app delegate to send app token to TestFlight.
Add empty core data model named MycoscopeModel
Update RestKit pod to 0.20.0rc1 from 0.20.0pre6
Import RestKit headers in app delegate.
Show network activity indicator in status bar.