MAGETWO-38838: Create composer management library and reuse it in both updater and setup wizard

- fixes and changes according CR

Author: Ivan Gavryshko

README.md

@@ -1 +1 @@
-Magento composer lib
+Magento composer library helps to instantiate Composer application and run composer commands.

app/code/Magento/Composer/MagentoComposerApplication.php

@@ -11,8 +11,17 @@
 use Composer\Factory as ComposerFactory;
 use Symfony\Component\Console\Output\BufferedOutput;
 
+/**
+ * Class MagentoComposerApplication
+ *
+ * This class provides ability to set composer application settings and run any composer command.
+ * Also provides method to get Composer instance so you can have access to composer properties lie Locker
+ */
 class MagentoComposerApplication
 {
+
+    const COMPOSER_WORKING_DIR = '--working-dir';
+
     /**
      * Trigger checks config
      *
@@ -41,6 +50,11 @@ class MagentoComposerApplication
      */
     private $consoleOutput;
 
+    /**
+     * @var ConsoleArrayInputFactory
+     */
+    private $consoleArrayInputFactory;
+
     /**
      * Constructs class
      *
@@ -109,7 +123,7 @@ public function runComposerCommand(array $commandParams)
 
         $this->consoleApplication->resetComposer();
 
-        $commandParams['--working-dir'] = dirname($this->composerJson);
+        $commandParams[self::COMPOSER_WORKING_DIR] = dirname($this->composerJson);
 
         $input = $this->consoleArrayInputFactory->create($commandParams);
 

composer.json

@@ -1,6 +1,6 @@
 {
   "name": "magento/composer",
-  "description": "Magento composer library helps to instantiate Composer application and run Symfony commands.",
+  "description": "Magento composer library helps to instantiate Composer application and run composer commands.",
   "type": "library",
   "version": "0.74.0-beta8",
   "license": [