Add PIPENV_REQUESTS_TIMEOUT and use it for requests session

[birdhackor]

Thank you for contributing to Pipenv!

The issue

When I was using pipelinev in an environment with network issues, I needed to increase the timeout setting for the connection to complete properly, but I found that the default behavior was set to 10 seconds and could not be changed, so I increased it.

The fix

Add a new ENV config for timeout, so that user can change it.

The checklist

• Associated issue
• A news fragment in the news/ directory to describe this fix with the extension .bugfix.rst, .feature.rst, .behavior.rst, .doc.rst. .vendor.rst. or .trivial.rst (this will appear in the release changelog). Use semantic line breaks and name the file after the issue number or the PR #.

[birdhackor]

Fix Unexpected token ) and remove extra space.

[matteius]

@birdhackor Please also update corresponding documentation for this new env var.

[birdhackor]

@birdhackor Please also update corresponding documentation for this new env var.

Seems docs/configuration.md use autoclass to generate documentation. I think it will automaticly use docstrings as documentation.

Am I missing anything that needs to be modified?

[matteius]

@birdhackor Just a new fragment then, and there is a conflict to resolve -- also there is a second spot now in that method where there is a conflict where you'll want to pass the configured var instead of 10.

[birdhackor]

@matteius I create a new PR #5907 (Re-send due to force push).