fix: Make mkdir resilient for multiple runs.

Author: BenHenning

package.json

@@ -23,8 +23,8 @@
     "wdio:build:app": "cd test/webdriverio && webpack",
     "wdio:build:tests": "tsc -p ./test/webdriverio/test/tsconfig.json",
     "wdio:clean": "cd test/webdriverio/test && rm -rf dist && rm -rf failures",
-    "wdio:run": "npm run wdio:build && cd test/webdriverio/test && mkdir failures && npx mocha dist",
-    "wdio:run:ci": "npm run wdio:build && cd test/webdriverio/test && mkdir failures && npx mocha --timeout 30000 dist"
+    "wdio:run": "npm run wdio:build && cd test/webdriverio/test && mkdir -p failures && npx mocha dist",
+    "wdio:run:ci": "npm run wdio:build && cd test/webdriverio/test && mkdir -p failures && npx mocha --timeout 30000 dist"
   },
   "main": "./dist/index.js",
   "module": "./src/index.js",