Replace underscore by lodash

Summary:As far as we agreed to merge `rnpm` into react-native core, we need to align our dependencies to exclude duplications. One of the steps forward would be to use the same utilities library. According to the thread on fb, everybody is fine with replacing underscore by lodash (which we use internally for rnpm).

So, here we go!

cc mkonicek davidaurelio grabbou

**Test plan**
```
$ npm test
```
![image](https://cloud.githubusercontent.com/assets/2273613/13173972/ee34c922-d700-11e5-971b-68ff7322b6d6.png)

**Code formatting**

Changes are aligned with the current [style guide](https://github.com/facebook/react-native/blob/master/CONTRIBUTING.md#style-guide).
Closes #6030

Differential Revision: D3016271

Pulled By: davidaurelio

fb-gh-sync-id: c4f6776a7de7470283d3ca5a8b56e423247f5e45
shipit-source-id: c4f6776a7de7470283d3ca5a8b56e423247f5e45

Author: Kureev Alexey

local-cli/server/formatBanner.js

@@ -8,7 +8,7 @@
  */
 'use strict';
 
-var _ = require('underscore');
+var _ = require('lodash');
 var wordwrap = require('wordwrap');
 
 var HORIZONTAL_LINE = '\u2500';
@@ -45,7 +45,7 @@ var BOTTOM_RIGHT = '\u2518';
 function formatBanner(message, options) {
   options = options || {};
   _.defaults(options, {
-    chalkFunction: _.identity,
+    chalkFunction: (fn) => fn,
     width: 80,
     marginLeft: 0,
     marginRight: 0,
@@ -71,7 +71,7 @@ function formatBanner(message, options) {
 
   var left = spaces(marginLeft) + VERTICAL_LINE + spaces(paddingLeft);
   var right = spaces(paddingRight) + VERTICAL_LINE + spaces(marginRight);
-  var bodyLines = _.flatten([
+  var bodyLines = _.flattenDeep([
     arrayOf('', paddingTop),
     body.split('\n'),
     arrayOf('', paddingBottom),
@@ -88,7 +88,7 @@ function formatBanner(message, options) {
     spaces(marginRight);
   var bottom = spaces(marginLeft) + BOTTOM_LEFT + horizontalBorderLine +
     BOTTOM_RIGHT + spaces(marginRight);
-  return _.flatten([top, bodyLines, bottom]).join('\n');
+  return _.flattenDeep([top, bodyLines, bottom]).join('\n');
 }
 
 function spaces(number) {

npm-shrinkwrap.json

@@ -151,6 +151,7 @@
     "json-stable-stringify": "^1.0.1",
     "json5": "^0.4.0",
     "jstransform": "^11.0.3",
+    "lodash": "^3.10.1",
     "mkdirp": "^0.5.1",
     "module-deps": "^3.9.1",
     "node-fetch": "^1.3.3",
@@ -169,7 +170,6 @@
     "stacktrace-parser": "^0.1.3",
     "temp": "0.8.3",
     "uglify-js": "^2.6.2",
-    "underscore": "^1.8.3",
     "wordwrap": "^1.0.0",
     "worker-farm": "^1.3.1",
     "ws": "^0.8.0",

package.json

@@ -14,7 +14,6 @@ require('fast-path').replace();
 useGracefulFs();
 
 var debug = require('debug');
-var omit = require('underscore').omit;
 var Activity = require('./src/Activity');
 
 exports.createServer = createServer;
@@ -118,6 +117,16 @@ function createNonPersistentServer(options) {
   return createServer(options);
 }
 
+function omit(obj, blacklistedKeys) {
+  return Object.keys(obj).reduce((clone, key) => {
+    if (blacklistedKeys.indexOf(key) === -1) {
+      clone[key] = obj[key];
+    }
+
+    return clone;
+  }, {});
+}
+
 // we need to listen on a socket as soon as a server is created, but only once.
 // This file also serves as entry point when spawning a socket server; in that
 // case we need to start the server immediately.

packager/react-packager/index.js

@@ -8,7 +8,7 @@
  */
 'use strict';
 
-const _ = require('underscore');
+const _ = require('lodash');
 const base64VLQ = require('./base64-vlq');
 const BundleBase = require('./BundleBase');
 const ModuleTransport = require('../lib/ModuleTransport');
@@ -143,7 +143,7 @@ class Bundle extends BundleBase {
 
       if (options.excludeSource) {
         if (map.sourcesContent && map.sourcesContent.length) {
-          map = _.extend({}, map, {sourcesContent: []});
+          map = Object.assign({}, map, {sourcesContent: []});
         }
       }