Use Yarn for Install/Uninstall CLI if available

Summary:
Make `react-native install` and `uninstall` cli to use yarn if available (fixes facebook#11122)

**Test plan Yarn**

1. Publish to Sinopia: https://github.com/facebook/react-native/tree/master/react-native-cli
2. react-native init AwesomeApp
3. react-native install react-native-fit-image
4. react-native uninstall react-native-fit-image

**Test plan NPM**
1. Publish to Sinopia: https://github.com/facebook/react-native/tree/master/react-native-cli
2. react-native init AwesomeAppNPM --npm
3. react-native install react-native-fit-image
4. react-native uninstall react-native-fit-image

**output (yarn.lock)**

```
> react-native install react-native-fit-image
yarn add v0.16.1
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
[3/4] 🔗  Linking dependencies...
[4/4] 📃  Building fresh packages...
success Saved lockfile.
success Saved 1 new dependency
└─ react-native-fit-image@1.4.6
✨  Done in 4.11s.
rnpm-install info Module react-native-fit-image has been successfully
Closes facebook#11174

Differential Revision: D4441872

fbshipit-source-id: 05bd30e1ad14bdbe861259c88e1f18df77cfa54f

local-cli/install/install.js

@@ -1,5 +1,16 @@
+/**
+ * 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 spawnSync = require('child_process').spawnSync;
 const log = require('npmlog');
+const PackageManager = require('../util/PackageManager');
 const spawnOpts = {
   stdio: 'inherit',
   stdin: 'inherit',
@@ -10,20 +21,20 @@ log.heading = 'rnpm-install';
 function install(args, config) {
   const name = args[0];
 
-  var res = spawnSync('npm', ['install', name, '--save'], spawnOpts);
+  let res = PackageManager.add(name);
 
   if (res.status) {
     process.exit(res.status);
   }
 
-  res = spawnSync('rnpm', ['link', name], spawnOpts);
+  res = spawnSync('react-native', ['link', name], spawnOpts);
 
   if (res.status) {
     process.exit(res.status);
   }
 
   log.info(`Module ${name} has been successfully installed & linked`);
-};
+}
 
 module.exports = {
   func: install,

local-cli/install/uninstall.js

@@ -1,5 +1,16 @@
+/**
+ * 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 spawnSync = require('child_process').spawnSync;
 const log = require('npmlog');
+const PackageManager = require('../util/PackageManager');
 const spawnOpts = {
   stdio: 'inherit',
   stdin: 'inherit',
@@ -10,20 +21,20 @@ log.heading = 'rnpm-install';
 function uninstall(args, config) {
   const name = args[0];
 
-  var res = spawnSync('rnpm', ['unlink', name], spawnOpts);
+  var res = spawnSync('react-native', ['unlink', name], spawnOpts);
 
   if (res.status) {
     process.exit(res.status);
   }
 
-  res = spawnSync('npm', ['uninstall', name], spawnOpts);
+  res = PackageManager.remove(name);
 
   if (res.status) {
     process.exit(res.status);
   }
 
   log.info(`Module ${name} has been successfully uninstalled & unlinked`);
-};
+}
 
 module.exports = {
   func: uninstall,

local-cli/link/link.js

@@ -141,7 +141,11 @@ function link(args, config) {
     return Promise.reject(err);
   }
 
-  const packageName = args[0];
+  let packageName = args[0];
+  // Check if install package by specific version (eg. package@latest)
+  if (packageName !== undefined) {
+    packageName = packageName.split('@')[0];
+  }
 
   const dependencies = getDependencyConfig(
     config,

local-cli/util/PackageManager.js

@@ -0,0 +1,74 @@
+/**
+ * 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 spawnSync = require('child_process').spawnSync;
+const yarn = require('../util/yarn');
+const spawnOpts = {
+  stdio: 'inherit',
+  stdin: 'inherit',
+};
+
+const projectDir = process.cwd();
+const isYarnAvailable =
+  yarn.getYarnVersionIfAvailable() &&
+  yarn.isGlobalCliUsingYarn(projectDir);
+
+/**
+ * Execute npm or yarn command
+ *
+ * @param  {String} yarnCommand Yarn command to be executed eg. yarn add package
+ * @param  {String} npmCommand  Npm command to be executed eg. npm install package
+ * @return {object}             spawnSync's result object
+ */
+function callYarnOrNpm(yarnCommand, npmCommand) {
+  let command;
+
+  if (isYarnAvailable) {
+    command = yarnCommand;
+  } else {
+    command = npmCommand;
+  }
+
+  const args = command.split(' ');
+  const cmd = args.shift();
+
+  const res = spawnSync(cmd, args, spawnOpts);
+
+  return res;
+}
+
+/**
+ * Install package into project using npm or yarn if available
+ * @param  {[type]} packageName Package to be installed
+ * @return {[type]}             spawnSync's result object
+ */
+function add(packageName) {
+  return callYarnOrNpm(
+    `yarn add ${packageName}`,
+    `npm install ${packageName} --save`
+  );
+}
+
+/**
+ * Uninstall package from project using npm or yarn if available
+ * @param  {[type]} packageName Package to be uninstalled
+ * @return {Object}             spawnSync's result object
+ */
+function remove(packageName) {
+  return callYarnOrNpm(
+    `yarn remove ${packageName}`,
+    `npm uninstall --save ${packageName}`
+  );
+}
+
+module.exports = {
+  add: add,
+  remove: remove,
+};