{
  "name": "aw/newsletter-bundle",
  "type": "symfony-bundle",
  "description": "Newsletter bundle",
  "keywords": ["newsletter"],
  "license": "MIT",
  "authors": [
    {
      "name": "Adam Wójs",
      "email": "adam@wojs.pl",
      "homepage": "http://adam.wojs.pl"
    }
  ],
  "require": {
    "php": ">=5.3.9",
    "symfony/framework-bundle": ">=2.7",
    "symfony/security-bundle": ">=2.7"
  },
  "require-dev": {
  },
  "autoload": {
    "psr-0": { "AW\\NewsletterBundle": "" }
  }
}

{
  "name": "aw/newsletter-bundle",
  "type": "symfony-bundle",
  "description": "Newsletter bundle",
  "keywords": ["newsletter"],
  "license": "MIT",
  "authors": [
    {
      "name": "Adam Wójs",
      "email": "adam@wojs.pl",
      "homepage": "http://adam.wojs.pl"
    }
  ],
  "require": {
    "php": ">=5.3.9",
    "symfony/framework-bundle": ">=2.7",
    "symfony/security-bundle": ">=2.7"
  },
  "require-dev": {
  },
  "autoload": {
    "psr-4": { "AW\\NewsletterBundle": "" }
  }
}

Update autoload from psr-0 to psr-4
Update autoload from psr-0 to psr-4