message: Improve composer installer
  Check to signature.
  Add error handling.
  See Also
diff: @@ -13,9 +13,23 @@ if [ "$version" != "$1" ]; then
  fi
  if [ ! -e "/usr/bin/composer" ]; then
  - sudo curl -s https://getcomposer.org/installer | php;
  - sudo mv composer.phar /usr/local/bin/composer;
  + EXPECTED_SIGNATURE="$(curl -s https://composer.github.io/installer.sig)"
  + curl -s -L https://getcomposer.org/installer > composer-setup.php
  + ACTUAL_SIGNATURE="$(php -r "echo hash_file('sha384', 'composer-setup.php');")"
  +
  + if [ "$EXPECTED_SIGNATURE" != "$ACTUAL_SIGNATURE" ]; then
  + >&2 echo 'ERROR: Invalid installer signature'
  + rm composer-setup.php
  + exit 1
  + fi
  +
  + COMPOSER_ALLOW_SUPERUSER=1
  + sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer
  + RESULT=$?
  + rm composer-setup.php
  + exit $RESULT
  fi
  +
  composer global require hirak/prestissimo > /dev/null 2>&1
  ini_file=$(php --ini | grep "Loaded Configuration" | sed -e "s|.*:s*||" | sed "s/ //g")
  ext_dir=$(/usr/bin/php -i | grep "extension_dir => /usr" | sed -e "s|.*=> s*||")
  