add core-js production dependency (#79395)

Spencer · spalger · spalger · commit 47526a85ed31 · 2020-10-04T21:36:43.000-07:00
Co-authored-by: spalger <spalger@users.noreply.github.com> (cherry picked from commit 9e1c44f)
diff --git a/package.json b/package.json
@@ -150,6 +150,7 @@
     "chokidar": "^3.4.2",
     "color": "1.0.3",
     "commander": "^3.0.2",
+    "core-js": "^3.6.5",
     "cypress-promise": "^1.1.0",
     "deep-freeze-strict": "^1.1.1",
     "del": "^5.1.0",
