Upgrade cached dependencies and remove vendor dir

[peter279k]

Changed log

• It's good to update the cached dependencies with composer.
• Remove the composer.phar because this is the package manager and it should not be under the Git version control.
• Removing the vendor folder because this folder is about the dependencies directory and generated by the composer.
  It should let this folder not be under Git version control.
• Since the fieryprophet/php-sandbox package is deprecated. Using the corveda/php-sandbox package instead.
• Since the Apache web document root has been changed on the latest eboraas/apache-php Docker image, using the $(pwd):/var/www/html volume path instead.
• Giving a name (phpepl) for the Docker container during docker run --name=phpepl -p 80:80 -v $(pwd):/var/www/html -d eboraas/apache-php command running.