Cleaned up a load of relations and optional stuff

ref #11

src/models/entities/RunnerGroup.ts

@@ -18,12 +18,11 @@ export abstract class RunnerGroup {
    * Autogenerated unique id (primary key).
    */
   @PrimaryGeneratedColumn()
-  @IsOptional()
   @IsInt()
   id: number;
 
   /**
-   * The group's first name.
+   * The group's name.
    */
   @Column()
   @IsNotEmpty()