Update README to show how to update the composer.lock file
Parse out client IPs from trusted LBs

Configure NGINX to trust internal Heroku and CloudFlare IPs to send
X-Forwarded-For headers.

NOTE: We are not trusting IPv6 addresses from CloudFlare right now because
parsing of IPv6 addresses is currently not supported by the Heroku NGINX
instance.

Resolves #5
Merge branch 'master' into prod