Lint request: Keep dependency lists tidy

[justinabrahms]

In #47, there were several dependencies which were removed.. but without a coresponding removal of use statements. This leads me to believe that we have a declared dependency on things.. but don't actually use them. We should have a linter which complains about stuff like that.

[erenatas]

Thanks for creating the issue for this. To find out which dependencies are not actually used, I used cargo shear, however it sometimes gives false positives, which is one of the reasons why I decided not to make part of CI yet. I think we can provide more guidance on that if needed though.