Consider HTTPS_PROXY environment variable to overcome corporate proxy issue

[sag1]

Is your feature request related to a problem? Please describe

Thank you for this excellent contribution. I have a requirement to serve static content from a private S3 bucket. However, access to S3 in my environment must be routed through a corporate proxy. Would it be possible to consider adding support for the HTTPS_PROXY environment variable and utilizing it when making calls to S3?

Describe the solution you'd like

Would it be possible to consider adding support for the HTTPS_PROXY environment variable and utilizing it when making calls to S3?

Describe alternatives you've considered

Additional context

Making S3 calls via corporate proxy