Add command line arguments to emulate boto3.session.Session() **kwargs

[tcram]

In order to better accommodate user configuration, we should add command line arguments identical to the keyword arguments used when creating a session via boto3.session.Session(). Same applies for creating a boto3 client. Command line arguments would be passed into isd_s3.get_session(). See boto3 session reference at https://boto3.amazonaws.com/v1/documentation/api/latest/reference/core/session.html for list of keywords.

Probably not all of these will be required, but I see a need for the following:

• aws_access_key_id
• aws_secret_access_key
• profile_name
• endpoint_url

I'll add this in the pyinstaller-dev branch, since I ran into this issue while building the CLI.