Moved to a "cleaner" directory structure

ref #11

src/models/entities/UserGroup.ts

@@ -0,0 +1,44 @@
+import { PrimaryGeneratedColumn, Column, OneToMany, Entity, ManyToOne } from "typeorm";
+import {
+  IsInt,
+  IsNotEmpty,
+  IsOptional,
+  IsString,
+} from "class-validator";
+import { Permission } from "./Permission";
+
+/**
+ * Defines the UserGroup interface.
+*/
+@Entity()
+export abstract class UserGroup {
+  /**
+   * Autogenerated unique id (primary key).
+   */
+  @PrimaryGeneratedColumn()
+  @IsOptional()
+  @IsInt()
+  id: number;
+
+  /**
+     * permissions
+     */
+  @ManyToOne(() => Permission, permission => permission.groups, { nullable: true })
+  permissions: Permission[];
+
+  /**
+   * The group's name
+   */
+  @Column()
+  @IsNotEmpty()
+  @IsString()
+  name: string;
+
+  /**
+   * The group's description
+   */
+  @Column({nullable: true})
+  @IsOptional()
+  @IsString()
+  description?: string;
+}