Write happy-path tests for common methods except applicants

[kaustavdm]

• [x] employees #38
• [x] branches
• [x] departments
• [x] subDepartments
• [x] businessUnits
• [x] teams
• [x] levels
• [ ] timeOffs
• [ ] roles
• [ ] jobPostings
• [ ] candidateSources
• [ ] userFunctions
• [ ] newHires