Minor fixes. node types downgraded.

Author: samarpan-b

src/models/user-modifiable-entity.model.ts

@@ -1,7 +1,6 @@
-import {belongsTo, property} from '@loopback/repository';
+import {property} from '@loopback/repository';
 
 import {BaseEntity} from './base-entity.model';
-import {UserTenant} from './user-tenant.model';
 
 export abstract class UserModifiableEntity extends BaseEntity {
   @property({