v1.1.5 Release

New release to pickup PR #50, #51, #53, #55

Highlights:

• Stop exposing some things as mutable to finish out threading cleanups.
• More complete use of atomic/nonatomic to go with the threading cleanups.
• More threading handing to avoid some races/deadlocks.

v1.1.4 Release

New release to pickup PR #45, #46, #47, #48

Highlights:

• Refactoring to expose a block for custom challenge handling.
• Threading cleanup and enforcement internally.
• Expanding some HeaderDoc comments about usage.

v1.1.3 Release

New release with #43 merged in to let other pods depend on it for the background task fixes and testing.

v1.1.2 Release

Named release for the podspec to get pushed with tvOS support included.

v1.1.1 Release

Cutting a new to capture a tweak to the callback queues that make them a little nicer to use (they default now instead of returning nil).

1.1.0 Release

Release cut to provide something for the podspec to point at.