Added php5-memcache to php5 setup

Also took the liberty of storing PHP sessions using memcache as well
Merge pull request #35 from FightTheCurrent/master

Added php5-memcache to php5 setup
enable and optimize opcache caching
Merge pull request #44 from FightTheCurrent/feature/opcache

Feature/opcache
Disable Opcache for dev environment
Merge pull request #48 from FightTheCurrent/feature/dev-disable-opcache

Disable Opcache for dev environment
Add fastcgi_param SCRIPT_FILENAME

This could be missing depending on Nginx package versions in Ubuntu so
we're adding it to ensure it's always there.
Always install memcached
Fix plugin name and parentheses.
Merge pull request #51 from c2itllc/readmeupdates

Fix plugin name and parentheses in README.
Merge pull request #2 from roots/master

update to latest bedrock-ansible master