build: bump cross-env from 5.1.4 to 5.1.5 in /examples/full-airbnb (#115)

Bumps [cross-env](https://github.com/kentcdodds/cross-env) from 5.1.4 to 5.1.5.
- [Release notes](https://github.com/kentcdodds/cross-env/releases)
- [Changelog](https://github.com/kentcdodds/cross-env/blob/master/CHANGELOG.md)
- [Commits](kentcdodds/cross-env@v5.1.4...v5.1.5)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

examples/full-airbnb/package.json

@@ -26,7 +26,7 @@
     "babel-eslint": "^8.2.3",
     "babel-loader": "8.0.0-beta.2",
     "copy-webpack-plugin": "^4.0.1",
-    "cross-env": "^5.0.5",
+    "cross-env": "^5.1.5",
     "css-loader": "^0.28.11",
     "eslint": "^4.15.0",
     "eslint-config-airbnb-base": "^12.1.0",

examples/full-airbnb/yarn.lock

@@ -2323,9 +2323,9 @@ create-hmac@^1.1.0, create-hmac@^1.1.2, create-hmac@^1.1.4:
     safe-buffer "^5.0.1"
     sha.js "^2.4.8"
 
-cross-env@^5.0.5:
-  version "5.1.4"
-  resolved "https://registry.yarnpkg.com/cross-env/-/cross-env-5.1.4.tgz#f61c14291f7cc653bb86457002ea80a04699d022"
+cross-env@^5.1.5:
+  version "5.1.5"
+  resolved "https://registry.yarnpkg.com/cross-env/-/cross-env-5.1.5.tgz#31daf7f3a52ef337c8ddda585f08175cce5d1fa5"
   dependencies:
     cross-spawn "^5.1.0"
     is-windows "^1.0.0"