Bump nuxt from 2.15.4 to 2.15.6 in /template

Bumps [nuxt](https://github.com/nuxt/nuxt.js) from 2.15.4 to 2.15.6.
- [Release notes](https://github.com/nuxt/nuxt.js/releases)
- [Changelog](https://github.com/nuxt/nuxt.js/blob/dev/RELEASE_PLAN.md)
- [Commits](nuxt/nuxt@v2.15.4...v2.15.6)

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

Author: dependabot-preview[bot]

template/package.json

@@ -25,7 +25,7 @@
     "@nuxtjs/eslint-config": "6.0.0",
     "less": "4.1.1",
     "less-loader": "7.0.1",
-    "nuxt": "2.15.4",
+    "nuxt": "2.15.6",
     "node-sass": "4.14.1",
     "sass-loader": "10.0.2",
     "stylus": "0.54.8",