Bump d3 from 5.14.2 to 5.15.0

Bumps [d3](https://github.com/d3/d3) from 5.14.2 to 5.15.0.
- [Release notes](https://github.com/d3/d3/releases)
- [Changelog](https://github.com/d3/d3/blob/master/CHANGES.md)
- [Commits](https://github.com/d3/d3/compare/v5.14.2...v5.15.0)

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

package.json

@@ -4,7 +4,7 @@
     "bootstrap": "^4.1.3",
     "bootswatch": "^4.4.1",
     "chosen-js": "^1.8.7",
-    "d3": "^5.9.2",
+    "d3": "^5.15.0",
     "d3-tip": "^0.9.1",
     "font-awesome": "^4.7.0",
     "highlight.js": "^9.17.1",