Implement removing and adding qualifications while creating or editing employees (#29)

Co-authored-by: Phan Huy Tran <p.tran@neusta.de>
Reviewed-on: #29
Reviewed-by: Constantin Simonis <constantin@simonis.lol>

src/app/services/employee-api.service.ts

@@ -25,6 +25,6 @@ export default class EmployeeApiService {
   }
 
   public update(employee: Employee, id: number) {
-    return this.http.patch(`${EmployeeApiService.BASE_URL}/employees/${id}`, employee)
+    return this.http.put(`${EmployeeApiService.BASE_URL}/employees/${id}`, employee)
   }
 }