Add SQLite support for easy setup (#336)

* Modifies schema to allow SQLite as a DB driver. SQLite is preinstalled in most OSes allowing for minimal prerequisites in the installation process.

* Removes Redis dependency and replaces "real" redis instance with ioredis-mock this is not feature complete and errors are expected.

* Updates medusa new command to only ask for Postgres credentials if the starter template has database_type === "postgres" in medusa-config.js

* Small improvements to bin resolution

* Improvements to endpoint stability

integration-tests/api/__tests__/store/customer.js

@@ -73,7 +73,7 @@ describe("/store/customers", () => {
         })
         .catch((err) => err.response);
 
-      expect(response.status).toEqual(409);
+      expect(response.status).toEqual(402);
     });
   });