Align setup.py and requirements.txt versions

[WarheadsSE]

Add missing dependencies to setup.py

Add by #62, without the entries in setup.py, pip install gsutil will result in non-functional installation.

File "/usr/local/lib/python3.9/site-packages/gcs_oauth2_boto_plugin/oauth2_client.py", line 57, in <module>
  from google_auth_httplib2 import Request as GoogleAuthRequest
ModuleNotFoundError: No module named 'google_auth_httplib2'

Update requirements.txt versions to align with setup.py for six

I noticed that these two did not agreed on the version of six, either, so I addressed that.

Closes #67

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[WarheadsSE]

CLA addressed, check needs re-run.

[googlyrahman]

Hi, I understand that this would be an issue with standalone plugin, but i want to understand how this is the problem with gsutil installation, as gsutil setup.py (https://github.com/GoogleCloudPlatform/gsutil/blob/master/setup.py#L55) consists of these dependencies. I've also tried doing a fresh installation on a fresh VM, and it works perfectly fine, as gsutil setup.py has those dependency.

[googlyrahman]

Thanks for bringing this to our attention, We were also discussing this internally, and decided to fix it.

[WarheadsSE]

Hi, I understand that this would be an issue with standalone plugin, but i want to understand how this is the problem with gsutil installation, as gsutil setup.py (https://github.com/GoogleCloudPlatform/gsutil/blob/master/setup.py#L55) consists of these dependencies.

Put simply, you are correct. As of 2 weeks ago, master of gsutil did indeed include that dependency. However, anyone who installed a version prior to that point in time, would have a floating dependency on this package, which would not have declared a functional requirement.

[stanhu]

For example, if you had run pip install gsutil==5.27 prior to the release of gcs-oauth2-boto-plugin v3.2, then you would run into this issue.

[WarheadsSE]

@googlyrahman @shilpi23pandey I have left this open, for the time being, in regards to change in requirements.txt. Consider it a reminder to address that.

#70 effectively took the changes from here, and #68, but placed them under different lines, and with your internal team as the author(s).

[shilpi23pandey]

@googlyrahman @shilpi23pandey I have left this open, for the time being, in regards to change in requirements.txt. Consider it a reminder to address that.

#70 effectively took the changes from here, and #68, but placed them under different lines, and with your internal team as the author(s).

Hi @WarheadsSE This issue was blocking a critical gsutil release which was raised internally so we had to take action ASAP. For the sake of time, we decided to fix it ourselves.

That said, thanks for the PR and logging the issue.