Fix Dependencies and Ignore Unnecessary Files; Fixes #44

[yifang-zhu-pge]

Fixes #44

1. Updated requirements.txt:

   • Added missing packages to ensure all dependencies are included.

2. Compatibility Fixes:

   • The code encountered a TypeError: __init__() got multiple values for argument 'schema' when using the latest versions of numpy, pandas, and sqlalchemy.
   • Resolved this issue by reverting to older versions of these packages. For more details, refer to this Stack Overflow post.
   • Ideally, the code should be updated to be compatible with the latest package versions, but this serves as a temporary workaround.

3. Ignored .pkl Files:

   • Added .pkl files in the input_agent directory to .gitignore.

4. Ignored venv Directory:

   • Added the venv directory to .gitignore for users who prefer using venv over Anaconda.