Revert "Expose the actual transformer in the config"

This reverts commit bdc0f3031a.

local-cli/bundle/buildBundle.js

@@ -44,9 +44,9 @@ async function buildBundle(
     sourceMapUrl = path.basename(sourceMapUrl);
   }
 
-  config.transformerPath = args.transformer
+  config.transformModulePath = args.transformer
     ? path.resolve(args.transformer)
-    : config.transformerPath;
+    : config.transformModulePath;
 
   const requestOpts: RequestOptions = {
     entryFile: args.entryFile,

local-cli/dependencies/dependencies.js

@@ -25,9 +25,9 @@ async function dependencies(argv, configPromise, args, packagerInstance) {
   }
 
   config.cacheStores = [];
-  if (args.transformer) {
-    config.transformer.babelTransformerPath = path.resolve(args.transformer);
-  }
+  config.transformModulePath = args.transformer
+    ? path.resolve(args.transformer)
+    : config.transformModulePath;
 
   const relativePath = path.relative(
     config.projectRoot,

local-cli/util/Config.js

@@ -76,10 +76,8 @@ const Config = {
       ],
       getPolyfills,
     },
-    transformer: {
-      babelTransformerPath: require.resolve('metro/src/reactNativeTransformer'),
-    },
     watchFolders: getWatchFolders(),
+    transformModulePath: require.resolve('metro/src/reactNativeTransformer'),
   },
 
   async load(configFile: ?string): Promise<ConfigT> {