Merge pull request #429 from magento-okapis/MAGETWO-58700-Ui-Upgrade-2.1.2

Fixed issue:
 - MAGETWO-58700: UI upgrade failures during S2 builds 2.1.2

Author: Oleksii Korshenko

composer.json

@@ -36,7 +36,7 @@
         "colinmollenhour/php-redis-session-abstract": "1.1",
         "colinmollenhour/cache-backend-redis": "1.9",
         "colinmollenhour/cache-backend-file": "1.4",
-        "composer/composer": "1.0.0-beta1",
+        "composer/composer": "<=1.0.0-beta1",
         "monolog/monolog": "1.16.0",
         "oyejorge/less.php": "~1.7.0",
         "pelago/emogrifier": "0.1.1",