chore: upgrade testcafe

package.json

@@ -79,7 +79,7 @@
     "smtp-server": "^3.3.0",
     "string-replace-loader": "^1.2.0",
     "style-loader": "^0.21.0",
-    "testcafe": "^0.19.2",
+    "testcafe": "^0.20.5",
     "testcafe-react-selectors": "^2.0.0",
     "url-loader": "^0.6.2",
     "webpack": "^3.11.0",