Don't try to re-create master as a new branch.
Expect a Git error raised when the file it too large.

This MR addresses the following issue:
https://gitlab.com/gitlab-org/gitlab-ce/issues/57043
Based on the following comment:
https://gitlab.com/gitlab-org/gitlab-ce/issues/57043#note_136663994

gitlab-qa accepts an env var named GITLAB_QA_ACCESS_TOKEN, but here we
only accepted PERSONAL_ACCESS_TOKEN.

This change replaces PERSONAL_ACCESS_TOKEN with GITLAB_QA_ACCESS_TOKEN

First attempt at allowing a feature flag to be set via the command line
when running tests. This will enable the flag, run the tests, and then
disable the flag.

Using OptionParser meant changing how scenarios get the instance
address, so this also allows the address to be set as a command line
option. It's backwards compatible (you can still provide the address
as the command line option after the scenario)

The smoke test for AutoDevOps was previously failing.
This test is now passing and ready to be unquarantined

Fix url property format in urls.yml file

See merge request gitlab-org/gitlab-ce!26484

Also update arrivalRate to a max of 100

Also, make both `it` statments part of the same `describe`.

Finally, remove duplication of strings by defining variables and
re-using them.

The code should be written like a newspaper, wherein the top we
have more high level information, and as we go down we have more
details.

So I'm moving the implementation details to the bottom to make the
test easier to read.