Downgrade Project files in test and lib folders

[ArnoStrouwen]

Some Julia packages organize their tests using a Project file in the test folder, e.g.:
https://github.com/SciML/Optimization.jl/blob/master/test/Project.toml
If I understand this action correctly, the additional Project file will not be downgraded.

Similarly, there are sometimes additional Project files in the lib folder, e.g.:
https://github.com/SciML/Optimization.jl/blob/master/lib/OptimizationBBO/Project.toml

I think it would be a useful option to jointly downgraded all these Project files before testing.

[cjdoris]

Agreed. I think a good solution would be to add an argument to the action to specify the list of directories to look in. By default it would be . but in your example it would be .,test,lib/OptimizationBBO. What do you think?

[sethaxen]

Agreed, this would be useful to have.

[cjdoris]

I'll implement it soon. BTW this action has moved to https://github.com/julia-actions/julia-downgrade-compat now. I'm about to archive this repo.