Added server configuration examples

Added server configuration examples for Ubuntu, CentOS, Debian and Amazon Linux
Pass a target dir to Wrapper::create() so that composer.phar ends up in
our cache
Merge pull request #1934 from tk421/master

Added server configuration examples
Merge pull request #1937 from GawainLynch/hotfix/compser-wrapper-targetdir

Pass a target dir to Wrapper::create() so that composer.phar ends up in our cache