remove @babel/polyfill update mocha to use core-js

package.json

@@ -92,7 +92,7 @@
   },
   "devDependencies": {
     "@babel/cli": "^7.4.4",
-    "@babel/core": "^7.4.4",
+    "@babel/core": "^7.5.4",
     "@babel/preset-env": "^7.4.4",
     "@babel/register": "^7.4.4",
     "babel-eslint": "^10.0.1",

tests/mocha.opts

@@ -1,7 +1,7 @@
 --timeout 10000
 --recursive
 --retries 3
--r @babel/polyfill
+-r core-js/stable
 -r @babel/core
 -r @babel/register
 -r tests/globals

yarn.lock

@@ -26,7 +26,7 @@
   dependencies:
     "@babel/highlight" "^7.0.0"
 
-"@babel/core@^7.4.4":
+"@babel/core@^7.5.4":
   version "7.5.4"
   resolved "https://registry.yarnpkg.com/@babel/core/-/core-7.5.4.tgz#4c32df7ad5a58e9ea27ad025c11276324e0b4ddd"
   integrity sha512-+DaeBEpYq6b2+ZmHx3tHspC+ZRflrvLqwfv8E3hNr5LVQoyBnL8RPKSBCg+rK2W2My9PWlujBiqd0ZPsR9Q6zQ==
@@ -566,14 +566,6 @@
     "@babel/helper-regex" "^7.4.4"
     regexpu-core "^4.5.4"
 
-"@babel/polyfill@^7.4.4":
-  version "7.4.4"
-  resolved "https://registry.yarnpkg.com/@babel/polyfill/-/polyfill-7.4.4.tgz#78801cf3dbe657844eeabf31c1cae3828051e893"
-  integrity sha512-WlthFLfhQQhh+A2Gn5NSFl0Huxz36x86Jn+E9OW7ibK8edKPq+KLy4apM1yDpQ8kJOVi1OVjpP4vSDLdrI04dg==
-  dependencies:
-    core-js "^2.6.5"
-    regenerator-runtime "^0.13.2"
-
 "@babel/preset-env@^7.4.4":
   version "7.5.4"
   resolved "https://registry.yarnpkg.com/@babel/preset-env/-/preset-env-7.5.4.tgz#64bc15041a3cbb0798930319917e70fcca57713d"
@@ -1336,11 +1328,6 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/core-js-pure/-/core-js-pure-3.1.4.tgz#5fa17dc77002a169a3566cc48dc774d2e13e3769"
   integrity sha512-uJ4Z7iPNwiu1foygbcZYJsJs1jiXrTTCvxfLDXNhI/I+NHbSIEyr548y4fcsCEyWY0XgfAG/qqaunJ1SThHenA==
 
-core-js@^2.6.5:
-  version "2.6.9"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.9.tgz#6b4b214620c834152e179323727fc19741b084f2"
-  integrity sha512-HOpZf6eXmnl7la+cUdMnLvUxKNqLUzJvgIziQ0DiF3JwSImNphIqdGqzj6hIKyX04MmV0poclQ7+wjWvxQyR2A==
-
 core-js@^3.0.0, core-js@^3.1.4:
   version "3.1.4"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.1.4.tgz#3a2837fc48e582e1ae25907afcd6cf03b0cc7a07"
@@ -3917,11 +3904,6 @@ regenerate@^1.4.0:
   resolved "https://registry.yarnpkg.com/regenerate/-/regenerate-1.4.0.tgz#4a856ec4b56e4077c557589cae85e7a4c8869a11"
   integrity sha512-1G6jJVDWrt0rK99kBjvEtziZNCICAuvIPkSiUFIQxVP06RCVpq3dmDo2oi6ABpYaDYaTRr67BEhL8r1wgEZZKg==
 
-regenerator-runtime@^0.13.2:
-  version "0.13.2"
-  resolved "https://registry.yarnpkg.com/regenerator-runtime/-/regenerator-runtime-0.13.2.tgz#32e59c9a6fb9b1a4aff09b4930ca2d4477343447"
-  integrity sha512-S/TQAZJO+D3m9xeN1WTI8dLKBBiRgXBlTJvbWjCThHWZj9EvHK70Ff50/tYj2J/fvBY6JtFVwRuazHN2E7M9BA==
-
 regenerator-transform@^0.14.0:
   version "0.14.0"
   resolved "https://registry.yarnpkg.com/regenerator-transform/-/regenerator-transform-0.14.0.tgz#2ca9aaf7a2c239dd32e4761218425b8c7a86ecaf"