Merge fixes
This merge contains:
- New docker image with updated dependencies; anaconda removed
- Fix to gebco bathymetry
- Fix numpy deprecation warnings
- PEP8 formatting
- Refactored ocean module
- Docstrings and formatting in index module
- Updated install documentation as anaconda is no longer used
- Updated gitlab CI (downloaded testing data and resulting database should be cached if all tests are passing)
To be added:
- Deployment of documentation website to gitlab pages