Raise error if local_path or central_path does not point to project_name folder.

[JoeZiminski]

closes #180.

This PR enforces the local_path and central_path that the user inputs to the make_config_file to point to a folder with the same name as a the datashuttle project_name. This also required fixing a lot of tests which did not use this pattern.

Previously there was some discussion on the path that is passed to make_config_file. Currently it should be the folder path including the project folder name. This was also documented incorrectly.

The two would be to to fix the local_path and central_path to include the project-folder name, or fix the folder above and infer the project folder from the name of the initialised datashuttle project. After some back and forth (with myself) in this PR I went for the former for the below two reasons:

1. Under the hood, the 'local_path' and 'central_path' should intuitively point to the project folder. Then searches are simply local_path / rawdata rather than local_path / project_name / "rawdata". The latter could be added as a getter-function but is an extra level of complexity / maintenance that provides no benefit. It provides no benefit because for an instantiated project, we never want to switch between project folders, and so the config local_path should always point to the specific project folder.

2. It adds a level of robustness, in that it forces the user to input a path that explicitly matches the project_name they have input. We could search dynamically that the correct folder name exists in a root directory, but it seems easier to nip this in the bud at the offset and ensure everything is already aligned at the level of the config file.

Would be good to hear if this makes sense!

[niksirbi]

Hey @JoeZiminski. I agree with the choice you've made here. I was convinced by your arguments for choosing this way over the alternative. The implementation seems to work.

I only left one minor comment concerning the example paths in the documentation.

Feel free to merge this.

[JoeZiminski]

Thanks a lot for the suggestions @niksirbi !