Roave#157 report current tool version in CLI --version

Fixes Roave#157

Author: Ocramius

bin/roave-backward-compatibility-check.php

@@ -7,6 +7,7 @@
 use Composer\Factory;
 use Composer\Installer;
 use Composer\IO\ConsoleIO;
+use PackageVersions\Versions;
 use Roave\BackwardCompatibility\Command;
 use Roave\BackwardCompatibility\CompareClasses;
 use Roave\BackwardCompatibility\DetectChanges\BCBreak\ClassBased;
@@ -51,7 +52,7 @@
         throw new RuntimeException('Could not find Composer autoload.php');
     })();
 
-    $application = new Application();
+    $application = new Application('roave/backward-compatibility-check', Versions::getVersion('roave/backward-compatibility-check'));
     $helperSet   = $application->getHelperSet();
     $input       = new ArgvInput();
     $output      = new ConsoleOutput();

composer.json

@@ -7,6 +7,7 @@
         "beberlei/assert": "^3.2.1",
         "composer/composer": "^1.9.0",
         "nikolaposa/version": "^3.1.0",
+        "ocramius/package-versions": "^1.5.1",
         "roave/better-reflection": "^3.4.0",
         "symfony/console": "^4.3.3",
         "symfony/process": "^4.3.4",