Logging proxy and multipart request fixes

The following changes are included in the release:

• Ability to proxy logs
• Fix header providers in multipart requests

PRs included

• 5.0.0 by @mrandrewsmith in #141
• Update xcresultparser by @mrandrewsmith in #146
• Logging improvement by @mrandrewsmith in #144
• Header providers for multipart request by @mrandrewsmith in #145

Full Changelog: 5.0.0...5.0.1