Bump tailwindcss from 2.1.0 to 2.2.15

Bumps [tailwindcss](https://github.com/tailwindlabs/tailwindcss) from 2.1.0 to 2.2.15.
- [Release notes](https://github.com/tailwindlabs/tailwindcss/releases)
- [Changelog](https://github.com/tailwindlabs/tailwindcss/blob/master/CHANGELOG.md)
- [Commits](tailwindlabs/tailwindcss@v2.1.0...v2.2.15)

---
updated-dependencies:
- dependency-name: tailwindcss
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

package.json

@@ -55,7 +55,7 @@
     "seedrandom": "^3.0.5",
     "simple-functional-loader": "^1.2.1",
     "stringify-object": "^3.3.0",
-    "tailwindcss": "^2.1.0",
+    "tailwindcss": "^2.2.15",
     "tinytime": "^0.2.6",
     "unist-util-visit": "^2.0.3"
   },