Update dependency core-js to v2.6.6 (https://github.com/woocommerce/woocommerce-blocks/pull/573)

plugins/woocommerce-blocks/package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@woocommerce/block-library",
-  "version": "2.1.0",
+  "version": "2.2.0-dev",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -1985,7 +1985,6 @@
         "@wordpress/keycodes": "2.0.5",
         "@wordpress/viewport": "2.3.0",
         "classnames": "2.2.6",
-        "core-js": "2.6.5",
         "d3-axis": "^1.0.12",
         "d3-format": "^1.3.2",
         "d3-scale": "^2.1.2",
@@ -6785,9 +6784,9 @@
       "dev": true
     },
     "core-js": {
-      "version": "2.6.5",
-      "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.6.5.tgz",
-      "integrity": "sha512-klh/kDpwX8hryYL14M9w/xei6vrv6sE8gTHDG7/T/+SEovB/G4ejwcfE/CBzO6Edsu+OETZMZ3wcX/EjUkrl5A=="
+      "version": "2.6.6",
+      "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.6.6.tgz",
+      "integrity": "sha512-Mt/LaAym54NXnrjEMdo918cT2h70tqb/Yl7T3uPHQHRm5SxVoqlKmerUy4mL11k8saSBDWQ7ULIHxmeFyT3pfg=="
     },
     "core-js-compat": {
       "version": "3.0.0",

plugins/woocommerce-blocks/package.json

@@ -47,7 +47,7 @@
     "chalk": "2.4.2",
     "classnames": "2.2.6",
     "clean-webpack-plugin": "2.0.2",
-    "core-js": "2.6.5",
+    "core-js": "2.6.6",
     "cross-env": "5.2.0",
     "css-loader": "2.1.1",
     "cssnano": "4.1.10",