Pybuildkite

Ability to include retried jobs to be returned when fecthing builds

- Add PATCH call to the client
- Allow for pipelines to be updates
- Improve functionality for artifact downloading

Full REST API
This release marks full coverage of the Buildkite REST api

Added:
- Teams and Users endpoint support 41 and 44
- Use of an authorization header for token security 42

Maintenance
- Bug fixes
- 95% test coverage

- Fixes bug regarding `meta_data` when querying builds
- Fixes inverted job and build functions for querying artifacts

Bug Fixes:
- Fixed a bug which didn't allow you to query builds using a single Build State.
- Fixed bugs with the jobs endpoint which caused 500s

- Added the ability to perform pagination to ensure that users can get all results from the Buildkite API

v.0.0.3
- We've added the ability to have multiple build states to your queries so you can check for Running and Scheduled builds (for example)
- We've also upped the standard items per page to the max 100