Implement deleting qualifications (#24)

Co-authored-by: Phan Huy Tran <p.tran@neusta.de>
Reviewed-on: #24
Reviewed-by: Constantin Simonis <constantin@simonis.lol>

src/app/services/qualification.service.ts

@@ -25,4 +25,8 @@ export default class QualificationService {
   public edit(id: number, data: any) {
     return this.http.put(`${QualificationService.BASE_URL}/qualifications/${id}`, data)
   }
+
+  delete(id: number) {
+    return this.http.delete(`${QualificationService.BASE_URL}/qualifications/${id}`)
+  }
 }