Adjust rnpm link to colorize skipped linking steps

Summary:
Sometimes when working with a team of developers, someone adds a library but does not link it. To identify if this required linking, you have to type react-native link and then read a wall of text to see if rnpm handled the issue. This can be sped up with a friendly logging level for previously linked messages.

Continuation of #9507

![image](https://cloud.githubusercontent.com/assets/997157/17908676/119884a2-6947-11e6-8297-818fefed26a0.png)

![image](https://cloud.githubusercontent.com/assets/997157/17908687/1bad1b56-6947-11e6-9cf5-b8eec1f2d6ef.png)
Closes https://github.com/facebook/react-native/pull/9551

Differential Revision: D3821468

Pulled By: bestander

fbshipit-source-id: 3e83bf46454519debdd95cf3d5e8561e3c77364a

local-cli/__mocks__/chalk.js

@@ -0,0 +1,33 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+'use strict';
+
+const mockColor = () => {
+  return {
+    bold: () => { return { }; },
+  };
+};
+
+mockColor.bold = function() {
+  return {};
+};
+
+module.exports = {
+  dim: s =>  s,
+  magenta: mockColor,
+  white: mockColor,
+  blue: mockColor,
+  yellow: mockColor,
+  green: mockColor,
+  bold: mockColor,
+  red: mockColor,
+  cyan: mockColor,
+  gray: mockColor,
+  black: mockColor,
+};

local-cli/link/__tests__/link.spec.js

@@ -1,3 +1,12 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
 'use strict';
 
 jest.autoMockOff();
@@ -5,6 +14,10 @@ jest.autoMockOff();
 const sinon = require('sinon');
 const log = require('npmlog');
 const path = require('path');
+jest.setMock(
+  'chalk',
+  { grey: (str) => str, }
+);
 
 describe('link', () => {
   beforeEach(() => {

local-cli/link/link.js

@@ -1,7 +1,17 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
 const log = require('npmlog');
 const path = require('path');
 const uniq = require('lodash').uniq;
 const flatten = require('lodash').flatten;
+const chalk = require('chalk');
 
 const isEmpty = require('lodash').isEmpty;
 const promiseWaterfall = require('./promiseWaterfall');
@@ -30,7 +40,7 @@ const linkDependencyAndroid = (androidProject, dependency) => {
   const isInstalled = isInstalledAndroid(androidProject, dependency.name);
 
   if (isInstalled) {
-    log.info(`Android module ${dependency.name} is already linked`);
+    log.info(chalk.grey(`Android module ${dependency.name} is already linked`));
     return null;
   }
 
@@ -56,7 +66,7 @@ const linkDependencyIOS = (iOSProject, dependency) => {
   const isInstalled = isInstalledIOS(iOSProject, dependency.config.ios);
 
   if (isInstalled) {
-    log.info(`iOS module ${dependency.name} is already linked`);
+    log.info(chalk.grey(`iOS module ${dependency.name} is already linked`));
     return;
   }
 
@@ -82,7 +92,7 @@ const linkAssets = (project, assets) => {
     copyAssetsAndroid(assets, project.android.assetsPath);
   }
 
-  log.info(`Assets have been successfully linked to your project`);
+  log.info('Assets have been successfully linked to your project');
 };
 
 /**
@@ -126,11 +136,11 @@ function link(args, config) {
   return promiseWaterfall(tasks).catch(err => {
     log.error(
       `It seems something went wrong while linking. Error: ${err.message} \n`
-      + `Please file an issue here: https://github.com/facebook/react-native/issues`
+      + 'Please file an issue here: https://github.com/facebook/react-native/issues'
     );
     throw err;
   });
-};
+}
 
 module.exports = {
   func: link,