Update to Babel 7

.babelrc

@@ -1,4 +1,4 @@
-{ "presets": [ [ "env"
+{ "presets": [ [ "@babel/env"
                , { "targets": { "browsers": [ "last 2 chrome versions"
                                             , "last 2 chromeandroid versions"
                                             , "firefox esr"

package.json

@@ -1,7 +1,8 @@
 {
   "dependencies": {
-    "babel-cli": "^6.26.0",
-    "babel-preset-env": "^1.7.0",
+    "@babel/cli": "^7.0.0",
+    "@babel/core": "^7.0.0",
+    "@babel/preset-env": "^7.0.0",
     "requirejs": "^2.3.5",
     "terser": "^3.8.1"
   }