Bump chart.js from 2.8.0 to 2.9.3

Bumps [chart.js](https://github.com/chartjs/Chart.js) from 2.8.0 to 2.9.3.
- [Release notes](https://github.com/chartjs/Chart.js/releases)
- [Commits](https://github.com/chartjs/Chart.js/compare/v2.8.0...v2.9.3)

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

package.json

@@ -14,7 +14,7 @@
     "animate-sass": "^0.8.2",
     "axios": "^0.19",
     "bootstrap-sass": "^3.4.1",
-    "chart.js": "^2.8.0",
+    "chart.js": "^2.9.3",
     "cross-env": "^5.1",
     "es5-shim": "^4.5.14",
     "flatpickr": "^4.5.7",