Changed calendar version to 2.2.7

Author: ManukMinasyan

package.json

@@ -6,7 +6,7 @@
   },
   "name": "vue-functional-calendar",
   "description": "A style-uninstallable datepicker component for Vue.js",
-  "version": "2.2.6",
+  "version": "2.2.7",
   "license": "MIT",
   "repository": {
     "type": "git",
@@ -54,6 +54,7 @@
     "lint": "vue-cli-service lint"
   },
   "dependencies": {
+    "core-js": "^2.6.5",
     "vue": "^2.5.21"
   },
   "devDependencies": {
@@ -70,7 +71,6 @@
     "jest": "^16.0.1",
     "less": "^3.8.1",
     "less-loader": "^4.1.0",
-    "mini-css-extract-plugin": "^0.4.5",
     "node-sass": "^4.9.4",
     "sass-loader": "^7.1.0",
     "sass-resources-loader": "^1.3.4",