upgrade to babel 7, upgrade gulp-babel & babel-loader to work with babel 7

Author: that1matt

.babelrc

@@ -0,0 +1,34 @@
+module.exports = function (api) {
+  // const env = api.env()
+  // api.cache.using(() => process.env.NODE_ENV === 'development')
+  api.cache.never();
+
+  return {
+    presets: ['@babel/preset-env', '@babel/preset-react'],
+    plugins: [
+      // Stage 0
+      '@babel/plugin-proposal-function-bind',
+
+      // Stage 1
+      '@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',
+
+      // Stage 2
+      ['@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',
+
+      // Stage 3
+      '@babel/plugin-syntax-dynamic-import',
+      '@babel/plugin-syntax-import-meta',
+      ['@babel/plugin-proposal-class-properties', { loose: false }],
+      '@babel/plugin-proposal-json-strings',
+    ],
+  };
+};