Scoped: remove old references to default enabled syntax plugins, fix bootstrap [skip ci]

packages/babel-plugin-transform-async-to-module-method/package.json

@@ -11,7 +11,6 @@
   "dependencies": {
     "@babel/helper-module-imports": "7.0.0-beta.3",
     "@babel/helper-remap-async-to-generator": "7.0.0-beta.3",
-    "babel-plugin-syntax-async-functions": "7.0.0-beta.0",
     "@babel/types": "7.0.0-beta.3"
   },
   "devDependencies": {

packages/babel-plugin-transform-async-to-module-method/src/index.js

@@ -1,13 +1,10 @@
 import remapAsyncToGenerator from "@babel/helper-remap-async-to-generator";
-import syntaxAsyncFunctions from "@babel/plugin-syntax-async-functions";
 
 import { addNamed } from "@babel/helper-module-imports";
 
 export default function({ types: t }, options) {
   const { method, module } = options;
   return {
-    inherits: syntaxAsyncFunctions,
-
     visitor: {
       Function(path, state) {
         if (!path.node.async || path.node.generator) return;