Expose currentRequest in SessionDataTask

Thank you https://github.com/ocurr for this approach.

Exposes currentRequest for supporting request logging

Fix Swift 5.1: unrecognized selector sent to instance

Fix "[Session defaultTaskGroup]: unrecognized selector sent to instance" for Swift 5.1
#93

Thanks https://github.com/m-herold

2.0.0: Swift 5

• Swift 5 support (#90)

CocoaPods Update

Merge pull request #89 from dmiluski/chore/CocoaPods_4_2_Support

PodSpec Update: Sync to latest Release

Swift 4.2 Support

Merge pull request #86 from dmiluski/chore/AllTargetsToSwift_4_2

Bump all targets to Swift Version 4.2

v1.2.0: The One With SPM Support

• Adds support for Swift Package Manager #73 (thanks @loudmouth!)
• Fixes issue with error status codes not being recorded #75 (thanks @sethhoward!)
• Adds support for tvOS target for CocoaPods #71 (thanks @florianbuerger!)
• Misc CI improvements

1.1: Swift 4 + Xcode 9

• Swift 3.2-4 compatibility.
• Xcode 9 recommended build settings.

1.0.1: What is time, anyway?

Fixes

• A crash due to a cassette's interactions failing to deserialize from JSON.

1.0: Swift 3

• [UPDATED] Swift 3 compatibility #65

0.4: Swift 2.3 Compatibility

Merge pull request #58 from venmo/swift-23

Migrate to Swift 2.3