message: Fix report service for unit details
diff: import {Injectable} from '@angular/core';
  import {DataService} from '../data.service';
  import {BackendService} from '../backend.service';
  -import {IUser} from '../../../../../../../shared/models/IUser';
  @Injectable()
  export class ReportService extends DataService {
  @@ -28,8 +27,7 @@ export class ReportService extends DataService {
  getUnitDetailForCourse(courseId: string, unitId: string) {
  const originalApiPath = this.apiPath;
  this.apiPath += 'details/courses/' + courseId + '/units/';
  - // FIXME: Why do we expect an array?
  - const promise = this.readSingleItem<IUser[]>(unitId);
  + const promise = this.readSingleItem(unitId);
  this.apiPath = originalApiPath;
  return promise;
  }
  