revert fullStack test for core

It would have been better to add the coreInstaller in a new FullStack
test instead of replacing the current test for the magento core

Author: Flyingmana

tests/FullStackTest/magento/composer.json

@@ -21,6 +21,9 @@
         "magento-root-dir": "../htdocs/"
     },
     "require": {
-        "magento/core": "*"
+        "magento-hackathon/magento-composer-installer": "*",
+        "theseer/autoload": "~1.14",
+        "zetacomponents/console-tools": "dev-master",
+        "connect20/mage_all_latest": "*"
     }
 }