Switching to definitely assigned parameters

This allows us to go in "full strict mode" (yeah!)
See https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-7.html#strict-class-initialization

front/src/Phaser/Entity/RemotePlayer.ts

@@ -7,8 +7,6 @@ import {Character} from "../Entity/Character";
  */
 export class RemotePlayer extends Character {
     userId: string;
-    previousDirection: string;
-    wasMoving: boolean;
 
     constructor(
         userId: string,