fix: upgrade pretty-format to v24 (#195)

Author: SimenB

package.json

@@ -41,7 +41,7 @@
   "dependencies": {
     "@babel/runtime": "^7.1.5",
     "@sheerun/mutationobserver-shim": "^0.3.2",
-    "pretty-format": "^23.6.0",
+    "pretty-format": "^24.0.0",
     "wait-for-expect": "^1.1.0"
   },
   "devDependencies": {