Endpoint mod auto gen from openapi3 spec

[shivahari]

Added API Auto Generation capability to the framework. This new change will help generate *_endpoint.py modules from an OpenAPI v3.0 spec. This partially automates creating API Automation test.

Run python api_auto_generator/endpoint_module_generator.py --help to get Help on how to run the generator script.

Changes include:

• Adding a directory - api_auto_generator to house:

1. API Auto generator scripts
2. A Jinja2 template

• Added a generic method - make_request to make HTTP requests
• Updated requirements.txt file to add required modules