Building a Swift HTTP framework

This will be built while following Dave DeLong's HTTP in Swift, an 18-part series on building an HTTP framework in Swift. This project is primarily focused on personal learning, PRs may not be accepted. Raise an issue to suggest a different approach, resource or idea not discussed in the series.

1. An Intro to HTTP
2. Basic Structures
3. Request Bodies
4. Loading Requests
5. Testing and Mocking
6. Chaining Loaders
7. Dynamically Modifying Requests
8. Request Options
9. Resetting
10. Cancellation
11. Throttling
12. Retrying
13. Basic Authentication
14. OAuth Setup
15. OAuth
16. Composite Loaders
17. Brain Dump
18. Wrapping Up