Thread Safety and Race Condition Bug Fixes

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Added

• New .swift-version file to repo and reactivated pod lib lint in Travis file.
  • Added by Christian Noon.
• The OS_ACTIVITY_MODE environment variable to disable excessive logging.
  • Added by Christian Noon.

Updated

• The Alamofire submodule to the 4.0.1 release.
  • Updated by Christian Noon.

Fixed

• Issue where delay timers were being added to main run loop from non-main queues.
  • Fixed by Christian Noon in regards to Issue
    #16.
• Issue where spinner could be left up indefinitely due to decrement race condition.
  • Fixed by Christian Noon in regards to Issue
    #14.