Checkout V2: Update authorization from Basic to Bearer

[sinourain]

Start sending requests using http Auth:Bearer

Spreedly reference: ECS-3487

Unit: 66 tests, 403 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications 100% passed 2821.48 tests/s, 17228.11 assertions/s

Remote: 103 tests, 254 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications 100% passed 0.63 tests/s, 1.56 assertions/s

[github-actions[bot]]

To provide a cleaner slate for the maintenance of the library, this PR/Issue is being labeled stale after 60 days without activity. It will be closed in 14 days unless you comment with an update regarding its applicability to the current build. Thank you!

[github-actions[bot]]

To provide a cleaner slate for the maintenance of the library, this PR/Issue is being labeled stale after 60 days without activity. It will be closed in 14 days unless you comment with an update regarding its applicability to the current build. Thank you!