Increase memory limit for OSX tests

Signed-off-by: Michal Čihař <michal@cihar.com>

.travis.yml

@@ -73,6 +73,7 @@ matrix:
         - brew update
         - brew install gettext php70 mariadb
         - brew link --force gettext
+        - sed -i 's/^memory_limit = .*/memory_limit = -1/' /usr/local/etc/php/7.0/php.ini
         - curl https://getcomposer.org/installer | php
         - ln -s "`pwd`/composer.phar" /usr/local/bin/composer
         - mysql.server start