Cookie authentication

[alxwrd]

Summary

This adds a new method of authenticating with the API. The API can be accessed by providing the ACT_SSO_COOKIE cookie. This cookie can be obtained by logging in to callofduty.com using a web browser, then manually extracting it using your browsers developer tools. While not perfect, it can work as a work around because of the current issues.

The branch is open for edits by maintainers, if you want to move anything around, feel free. I'm happy to make changes here. I've included the new CookieAuth in auth.py, but I can extract this out. I've called the new method Cookie, but I'm happy for that to be changed.

I've also moved setting the headers from the old authentication flow into the Auth class. This way the http calls aren't concered with authentication.

Addresses #68.

Checklist

• If code changes were made then they have been tested
  • I have updated the documentation to reflect the changes
• This Pull Request fixes an Issue
• This Pull Request adds something new (e.g. new method or parameters)
• This Pull Request is a breaking change (e.g. methods or parameters removed/renamed)
• This Pull Request is not a code change (e.g. Documentation or README)

[EthanC]

Implemented in v1.3.0, thanks!