Add virtualenv for PythonVirtualOperator Functionality

Summary

Adds virtualenv module for PythonVirtualOperator DAG to work properly 

Tasks

Contributor:

• Update Dockerfile, hardening_manifest.yaml and adhere to Iron Bank requirements
• Ensure container builds successfully in the Iron Bank pipeline prior to creating an Merge Request to Development.
• Provide justifications for findings in the VAT
• Open a Merge Request from your branch to development
• Apply the StatusReview label to this issue and wait for feedback

Note: You must manually apply the StatusReview label in order to have a CHT member review your merge request.

Iron Bank:

• Merge contributor branch to development
• Review findings and justifications
• Merge development to master and close issue

Note: If the above process is rejected for any reason, the Status::Verification label will be removed and the issue will be sent back to Open. Any comments will be listed in this issue for you to address. Once they have been addressed, you must re-add the Status::Verification label.

Questions?

Contact the Iron Bank team by commenting on this issue with your questions or concerns. If you do not receive a response, add /cc @ironbank-notifications/onboarding.

Additionally, Iron Bank hosts an AMA working session every Wednesday from 1630-1730EST to answer questions.

Please read the Iron Bank Documentation for more info