Merge pull request pinterest#150 from pinterest/2.0.1Release

2.0.1 release

Merge branch 'maicki-feature/add-download-progress'

missed nullability specifier

Merge pull request pinterest#86 from foursquare/check-nil-url

Guard against nil url in category methods

Up to 1.2.1 to fix podspec issues

Update podspec to 1.2

Update podspec for 1.1.2 release

Merge pull request pinterest#24 from jparise/canceled-unlock

Release our lock when we encounter a canceled task

Merge pull request pinterest#20 from pinterest/setOperationQOS

Set QOS / Thread priority

Add more contact info