Added class validation for the enum

ref #6

src/models/entities/Permission.ts

@@ -1,4 +1,5 @@
 import {
+  IsEnum,
   IsInt,
   IsNotEmpty
 } from "class-validator";
@@ -29,12 +30,14 @@ export class Permission {
    */
   @Column({ type: 'varchar' })
   @IsNotEmpty()
+  @IsEnum(PermissionTarget)
   target: PermissionTarget;
 
   /**
    * The action type
    */
   @Column({ type: 'varchar' })
+  @IsEnum(PermissionAction)
   action: PermissionAction;
 
   /**