ei's installation fails  (php7.0)

EasyInterface's installation guide is not working for php7.0

You should install:
**php7.0-xml**
`sudo apt-get install php7.0-xml`
Enable the lib in php.in:
uncomment the line: extension=php_xmlrpc.dll

And the webclient will requiere the apache's module headers 
`a2enmod headers`

We will add this info to the installation guide.