Fix issue of persisting lines from previous execution (#3)

* Fix issue of persisting lines from previous execution * set name for MaxInstructionsExceededException

Author: luciferankon

src/machine.js

@@ -28,6 +28,7 @@ class Machine {
  }
 
  load(program) {
+ this.lines = new Lines(this.maxLinesToExecute);
  let instructions = program.split(/\n/);
  instructions.forEach((instruction, index) => {
  let line;

src/maxInstructionsExceededException.js

@@ -1,6 +1,7 @@
 class MaxInstructionsExceededException extends Error {
  constructor(maxLinesToExecute) {
  super();
+ this.name = this.constructor.name;
  this.maxLinesToExecute = maxLinesToExecute;
  }
 }