Remove `retainLines` and `sourceMaps` options

Summary:
`retainLines` is no longer necessary with the much improved source map generation.
`sourceMaps` is handled by the transformer itself.

Reviewed By: cpojer

Differential Revision: D5237103

fbshipit-source-id: e5c6bf5aa9d553fce9c3f4d59b3ea0057d45cfdc

babel-preset/configs/main.js

@@ -40,8 +40,6 @@ var preset = {
     ['transform-es2015-for-of', { loose: true }],
     require('../transforms/transform-symbol-member'),
   ]),
-  retainLines: true,
-  sourceMaps: false,
 };
 
 var env = process.env.BABEL_ENV || process.env.NODE_ENV;

babel-preset/package.json

@@ -1,6 +1,6 @@
 {
   "name": "babel-preset-react-native",
-  "version": "1.9.2",
+  "version": "2.0.0-alpha.1",
   "description": "Babel preset for React Native applications",
   "main": "index.js",
   "repository": "https://github.com/facebook/react-native/tree/master/babel-preset",

jest/preprocessor.js

@@ -39,6 +39,7 @@ module.exports = {
         inlineRequires: true,
         platform: '',
         projectRoot: '',
+        retainLines: true,
       },
       src,
     }).code;