move zend-hydrator to require-dev to be able to be used in zf ~2.5

Author: samsonasik

composer.json

@@ -17,7 +17,6 @@
         "php": "^5.6|^7.0",
         "zendframework/zend-console": "^2.5",
         "zendframework/zend-db": "^2.5",
-        "zendframework/zend-hydrator": "^2.2",
         "zendframework/zend-json": "^2.5|^3.0",
         "zendframework/zend-log": "^2.5",
         "zendframework/zend-mail": "^2.5",
@@ -27,7 +26,8 @@
     "require-dev": {
         "kahlan/kahlan": "^3.0.0",
         "satooshi/php-coveralls": "^1.0",
-        "zendframework/zend-servicemanager": "^2.5|^3.0"
+        "zendframework/zend-servicemanager": "^2.5|^3.0",
+        "zendframework/zend-hydrator": "^2.2"
     },
     "autoload": {
         "psr-4": {