+ Fixed long-standing issues with database tests. The DB is now guarded by a mutex to prevent tests running in parallel
+ Added .drone.yml to run tests on a PR and on a push
+ The `add_item` command adds items to a location of type `Shop`
+ `selling` allows items to be queried
+ Items are not sorted yet
+ The user will be able to apply optional sorting params
+ Allowed the `insert` function of the DB to be used to update a model already in the DB
+ Clippy + Fmt