fixed errors in new version of contract map due mlflow changes that w…

[DavisAgyemang]

there was some imports issues that would not have worked when deploying the app on azure app service

[SamuelHLewis]

I think we've got a mismatch between the way that the environment is built locally vs on Azure, which causes the import statements to be different. Locally, I run
python -m pip install -e .
to install all of the files within src and its subfolders as importable modules. This means that I don't need to add src to any of the import statements, I can import them directly e.g.
from utils.file_to_string import file_to_string_processor

Sorry that this wasn't documented, I've added a section to the README which explains each step. I've also updated the github action config file (ci.yml) to do this step before running any of the tests. Finally, I've removed the src prefix from all of the imports so that they work after the src files are installed as internal.

I think that we should keep this PR because your requirements.in is a good addition, and we know that it works locally and on Azure. The only extra step we need is to add this line to the deployment process:
python -m pip install -e .

Hope that makes sense, but let me know if not!