Bump mixin-deep from 1.3.2 to 2.0.1

Bumps [mixin-deep](https://github.com/jonschlinkert/mixin-deep) from 1.3.2 to 2.0.1.
- [Release notes](https://github.com/jonschlinkert/mixin-deep/releases)
- [Commits](https://github.com/jonschlinkert/mixin-deep/compare/1.3.2...2.0.1)

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

package.json

@@ -36,7 +36,7 @@
     "lodash": "^4.17.13",
     "lodash.template": "^4.5.0",
     "micromatch": "^4.0.2",
-    "mixin-deep": "^1.3.2",
+    "mixin-deep": "^2.0.1",
     "node-sass": "^4.12.0",
     "regenerator-runtime": "^0.13.5",
     "set-value": "^2.0.1"