lemp: pass environment variables on to php-fpm
lemp: pass environment variables on to php-fpm

This allows us to set SANDSTORM=1 in the default environment block generated by
`spk init` and then call getenv("SANDSTORM") in PHP apps to see if they're
being run under Sandstorm or not.

dwrensha/vagrant-spk,ndarilek/vagrant-spk,sandstorm-io/vagrant-spk,ndarilek/vagrant-spk,ndarilek/vagrant-spk,dwrensha/vagrant-spk,sandstorm-io/vagrant-spk,dwrensha/vagrant-spk,sandstorm-io/vagrant-spk