Legacy: PHP 5.6 variant added

Also,

• Alphabetized most mods installed
• Cleaned up README, now reflects upstream maintainer's 7.1 support status
• Made NewRelic components explicit, if/when we downgrade to an older version for stability
• New Nginx version uptake 1.11.5 (1.11.5-0+xenial0)

FPM: added .ini vars as environment vars

• Moved additional .ini vars to env versions
• Removed cont-init.d setters
• Changed test compose file to be different value than maintainer

FPM Status: now available, locally

Accessible from within the container @ 127.0.0.1/__status, can now be polled as part of the application healthcheck. Add ?json for a formatted output.

Parent Nginx Update

Ingesting: https://github.com/behance/docker-nginx/releases/tag/6.1.0

NewRelic: stopped being symlinked by default

At some point, NewRelic's symlinks stopped being created during the installation. Now restored.

Yaml: added disabled php extension

Can be enabled on Ubuntu variants with phpenmod yaml

Intake of major parent rev

• Ubuntu 16.04 (from parent)
• Tightened goss test checks based on author’s feedback
• Fixed cleanup mechanism, dropping 50MB from layer cache
• Worked around any potential AUFS issues
• Prepped travis for more exhaustive docker-compose-based trials

Additional testing structure

• /tests/php-fpm now a central location
• worked around an AUFS permission bug

Goss > Added build-time testing

Added goss for serverspec-like validation at build time

Redis: added, but in disabled state

Merge pull request #91 from bryanlatten/feature-redis

Dockerfile: added redis (disabled) to all