Add season.service test (99%) and boss.service (100%)

src/models/season.model.ts

src/services/boss.service.spec.ts

src/services/boss.service.ts

src/services/season.service.spec.ts

test/__mocks__/bossData.mock.ts

test/__mocks__/seasonEntity.mock.ts

test/__mocks__/userSeasonData.mock.ts