Update Babel

Author: jonathantneal

.babelrc

@@ -1,6 +1,12 @@
 {
-  "presets": ["es2015-loose", "stage-0"],
-  "plugins": ["add-module-exports", "precompile-charcodes"],
+  "presets": [
+    ["@babel/preset-env", { "loose": true }]
+  ],
+  "plugins": [
+    "@babel/proposal-class-properties",
+    "add-module-exports",
+    "precompile-charcodes"
+  ],
   "env": {
     "development": {
       "sourceMaps": "inline"

.eslintrc.json

@@ -90,4 +90,4 @@
             ".json$"
         ]
     }
-}
+}