Bump babel-loader from 8.0.4 to 8.0.6 in /slides (#38)

Bumps [babel-loader](https://github.com/babel/babel-loader) from 8.0.4 to 8.0.6.
- [Release notes](https://github.com/babel/babel-loader/releases)
- [Changelog](https://github.com/babel/babel-loader/blob/master/CHANGELOG.md)
- [Commits](babel/babel-loader@v8.0.4...v8.0.6)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot[bot]

slides/package-lock.json

@@ -8,7 +8,7 @@
   },
   "devDependencies": {
     "@babel/core": "^7.4.4",
-    "babel-loader": "^8.0.4",
+    "babel-loader": "^8.0.6",
     "babel-preset-env": "^1.7.0",
     "css-loader": "^2.1.1",
     "file-loader": "^3.0.1",