fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/npm:debug:20170905

package.json

@@ -109,13 +109,13 @@
     "nodemon": "^2.0.4",
     "npm-merge-driver-install": "^2.0.0",
     "object-hash": "^2.0.1",
-    "pa11y-ci": "^2.4.0",
+    "pa11y-ci": "^3.0.0",
     "puppeteer": "^2.1.1",
     "replace": "^1.2.0",
     "revalidator": "^0.3.1",
     "robots-parser": "^2.1.1",
     "standard": "^14.3.1",
-    "start-server-and-test": "^1.11.3",
+    "start-server-and-test": "^1.11.6",
     "supertest": "^4.0.2",
     "webpack-dev-middleware": "^3.7.2",
     "website-scraper": "^4.2.0"