chore: Popper.js added to dependencies.

Author: woothu

package.json

@@ -59,6 +59,7 @@
     "@coreui/coreui-plugin-chartjs-custom-tooltips": "^1.2.0",
     "chart.js": "^2.7.3",
     "core-js": "^2.5.7",
+    "popper.js": "^1.14.6",
     "vue": "^2.5.17",
     "vue-clickaway": "^2.2.2",
     "vue-functional-data-merge": "^2.0.7",