update babel to 7

Author: chnbohwr

.babelrc

@@ -1,14 +1,25 @@
 {
   "presets": [
-    "env",
-    "react",
-    "stage-0"
+    "@babel/preset-env",
+    "@babel/preset-react"
   ],
   "plugins": [
-    "transform-runtime",
-    "transform-decorators-legacy",
-    "transform-class-properties",
-    "transform-object-rest-spread",
+    "@babel/plugin-proposal-function-bind",
+    "@babel/plugin-proposal-export-default-from",
+    "@babel/plugin-proposal-logical-assignment-operators",
+    ["@babel/plugin-proposal-optional-chaining", { "loose": false }],
+    ["@babel/plugin-proposal-pipeline-operator", { "proposal": "minimal" }],
+    ["@babel/plugin-proposal-nullish-coalescing-operator", { "loose": false }],
+    "@babel/plugin-proposal-do-expressions",
+    ["@babel/plugin-proposal-decorators", { "legacy": true }],
+    "@babel/plugin-proposal-function-sent",
+    "@babel/plugin-proposal-export-namespace-from",
+    "@babel/plugin-proposal-numeric-separator",
+    "@babel/plugin-proposal-throw-expressions",
+    "@babel/plugin-syntax-dynamic-import",
+    "@babel/plugin-syntax-import-meta",
+    ["@babel/plugin-proposal-class-properties", { "loose": false }],
+    "@babel/plugin-proposal-json-strings",
     "react-hot-loader/babel"
   ]
 }