Merge pull request #870 from Cheppers/extension-version-in-config-yaml

Fix #869 - "ext install" command ignores the version number in config…

src/PhpBrew/Command/ExtensionCommand/InstallCommand.php

@@ -160,7 +160,7 @@ public function execute($extName, $version = 'stable')
 
                 // not every project has stable branch, using master as default version
                 $args = array_slice(func_get_args(), 1);
-                if (!isset($args[0]) || $args[0] != $extConfig->version) {
+                if (empty($extConfig->version)) {
                     $extConfig->version = $provider->getDefaultVersion();
                 }