Adds yaml component as dev dependency

Author: Keith Kirk

composer.json

@@ -17,20 +17,21 @@
         "email": "kkirk@undergroundelephant.com"
     },
     "require": {
-        "php":                      ">=5.4.0",
-        "doctrine/common":          "~2.4",
+        "php": ">=5.4.0",
+        "doctrine/common": "~2.4",
         "symfony/dependency-injection": "~2.3|^3.0",
         "symfony/config": "~2.3|^3.0",
         "symfony/http-kernel": "~2.3|^3.0",
         "symfony/console": "~2.3|^3.0",
-        "symfony/monolog-bundle":   "~2.3|^3.0"
+        "symfony/monolog-bundle": "~2.3|^3.0"
     },
     "require-dev": {
-        "phpunit/phpunit":        "~3.7",
-        "aws/aws-sdk-php":        "~2.5",
-        "iron-io/iron_mq":        "^4.0",
-        "symfony/finder":         "~2.3|^3.0",
-        "symfony/filesystem":     "~2.3|^3.0"
+        "phpunit/phpunit": "~3.7",
+        "aws/aws-sdk-php": "~2.5",
+        "iron-io/iron_mq": "^4.0",
+        "symfony/finder": "~2.3|^3.0",
+        "symfony/filesystem": "~2.3|^3.0",
+        "symfony/yaml": "^3.4"
     },
     "suggest": {
         "aws/aws-sdk-php": "Required to use AWS as a Queue Provider",