title: How to setup travis-ci with Laravel 5? InvalidArgumentException
body: <p>I tried to run Travis-ci with Laravel 5.2 several times, but nothing works for me. I can run phpunit locally and it works, but not in travis.</p>
  
  <p>My current travis.yml:</p>
  
  <pre><code>language: php
  
  php:
    - 5.5
    - 5.6
    - 7.0
    #- hhvm
    #- nightly
  
  sudo: required
  
  before_script:
    - mkdir bootstrap/cache
    - mkdir storage
    - mkdir storage/framework
    - mkdir storage/framework/cache
    - sudo chmod -R 777 bootstrap/cache
    - sudo chmod -R 777 storage
    #- cp .env.travis .env
    - composer self-update
    - composer install --no-interaction
    #- php artisan key:generate
  
  script:
    - vendor/bin/phpunit
  </code></pre>
  
  <p>The latest error in travis is
  a failed request to [<a href="http://localhost]" rel="nofollow noreferrer">http://localhost]</a>. Received status code [500].
  Caused by exception 'InvalidArgumentException' with message 'Please provide a valid cache path.' in /home/travis/build/Saibamen/laravel5-travis/bootstrap/cache/compiled.php:15392</p>
  
  <p>All commits and travis logs are here: <a href="https://github.com/Saibamen/laravel5-travis/commits/master" rel="nofollow noreferrer">click</a></p>