fix typo in libs/remix-tests/tests/testRunner.spec.ts

libs/remix-tests/tests/testRunner.spec.ts

@@ -12,7 +12,7 @@ import { ResultsInterface, TestCbInterface, ResultCbInterface } from '../src/ind
 
 // deepEqualExcluding allows us to exclude specific keys whose values vary.
 // In this specific test, we'll use this helper to exclude `time` keys.
-// Assertions for the existance of these will be made at the correct places.
+// Assertions for the existence of these will be made at the correct places.
 function deepEqualExcluding(a: any, b: any, excludedKeys: string[]) {
   function removeKeysFromObject(obj: any, excludedKeys: string[]) {
     if (obj !== Object(obj)) {