InfiniteGpt should read from environment variables or take argument overrides when instantiated

[robTheBuildr]

Dependency on: #9

Acceptance Criteria

• The OpenApi key should be read an environment variable OPEN_API_KEY (default behavior)
• Users should be able to pass in their OpenApi Key as an argument override
• The __init(...) function of InfiniteGpt should take the same arguments (optionally) as configure(...) and should call configure itself if provided