Install php-curl 5.6 (Ubuntu)
1sudo apt-get install php5.6-curl
More info in https://stackoverflow.com/questions/40567133/cannot-add-ppa-ppaondrej-php5-5-6
1sudo apt-get install php5.6-curl
More info in https://stackoverflow.com/questions/40567133/cannot-add-ppa-ppaondrej-php5-5-6