* upstream/master: (28 commits)
  add the link for LICENSE
  Uninstall executables when uninstalling Bundler.
  Consistent naming.
  Update Travis configuration for Xcode 9.2.
  Preparing for the 3.2.0 release
  Fix typo
  Update content to reflect the newer RFC
  Clarify documentation for supported encodings in AFJSONResponseSerializer
  Rename Fastlane env scheme.
  Remove redundant iOS deployment target setting.
  Set Xcode compatibility to Xcode 6.3 and up.
  Change “OS X” to “macOS” across the board.
  Fix analyzer warning about memory leak.
  Fix analyzer warning about NULL dereference.
  Fix analyzer warning about mutable copies.
  Update project settings to Xcode 9.1 defaults.
  Update security policy test certificates (AFNetworking#4103)
  self in block
  Remove usage of XCTestExpectation.inverted (not supported)
  Remove usage of XCTestExpectation.inverted (not supported)
  ...