Replaced class with role

[Joseph-WhiteSWE]

Changes to be committed: modified: client/app/AppRoutes.js modified: client/app/store.js modified: client/features/chat/Chat.js deleted: client/features/class/classSlice.js renamed: client/features/class/class.js -> client/features/role/role.js new file: client/features/role/roleSlice.js modified: client/features/settings/SettingSelect.js modified: script/seed.js deleted: server/api/classes.js modified: server/api/index.js new file: server/api/roles.js modified: server/db/index.js deleted: server/db/models/Class.js new file: server/db/models/Role.js modified: server/db/models/User.js