Add support for proxy connections

[ejones18]

As per #12 ; adds support for proxy connections when making http or https requests using the requests lib as seen here: https://requests.readthedocs.io/en/latest/user/advanced/#proxies

Includes:

• Updated command line interface to include option to add http and https proxies,
• Handling for the above arguments,
• Further implementation to update the requests session to use the passed-in proxies.
• Updated README and version number.

Doesn't include:

• Updated sphinx documentation - review before generating

cc: @JamieTaylor-TUOS

[JamieTaylor-TUOS]

Fixes #18 Closes #6