fix: upgrade core-js from 2.6.2 to 2.6.12 (#328)

Snyk has created this PR to upgrade core-js from 2.6.2 to 2.6.12.

See this package in npm:
https://www.npmjs.com/package/core-js

See this project in Snyk:
https://app.snyk.io/org/kspearrin/project/38b1ffd6-0f49-4f56-b34f-c800f1e8b2aa?utm_source=github&utm_medium=upgrade-pr

package-lock.json

@@ -2710,9 +2710,9 @@
       "dev": true
     },
     "core-js": {
-      "version": "2.6.2",
-      "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.6.2.tgz",
-      "integrity": "sha512-NdBPF/RVwPW6jr0NCILuyN9RiqLo2b1mddWHkUL+VnvcB7dzlnBJ1bXYntjpTGOgkZiiLWj2JxmOr7eGE3qK6g=="
+      "version": "2.6.12",
+      "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.6.12.tgz",
+      "integrity": "sha512-Kb2wC0fvsWfQrgk8HU5lW6U/Lcs8+9aaYcy4ZFc6DDlo4nZ7n70dEgE5rtR0oG6ufKDUnrwfWL1mXR5ljDatrQ=="
     },
     "core-util-is": {
       "version": "1.0.2",

package.json

@@ -80,7 +80,7 @@
     "browser-hrtime": "^1.1.8",
     "chalk": "2.4.1",
     "commander": "7.0.0",
-    "core-js": "2.6.2",
+    "core-js": "2.6.12",
     "duo_web_sdk": "git+https://github.com/duosecurity/duo_web_sdk.git",
     "electron-log": "4.3.0",
     "electron-store": "6.0.1",