message: API: Remove unused imports
diff: import * as mongoose from 'mongoose';
  import {INotificationSettings} from '../../../shared/models/INotificationSettings';
  -import {Course, ICourseModel} from './Course';
  -import {IUserModel} from './User';
  +import {ICourseModel} from './Course';
  import {IUser} from '../../../shared/models/IUser';
  interface INotificationSettingsModel extends INotificationSettings, mongoose.Document {
  