Fix broken link to the default version of sphinx.

Fixes https://github.com/travis-ci/travis-ci/issues/2728
PHP updates
Pin OracleJDK 7 version to 7u60, 8 to 8u5
Merge pull request #365 from GrahamCampbell/php

PHP Updates
Document Oracle JDK changes
PHP memcached updates
PHP rabbitmq checkout the latest version
Merge pull request #367 from GrahamCampbell/php-memcached

PHP memcached updates
Merge pull request #368 from GrahamCampbell/php-amqp

PHP rabbitmq checkout the latest version
Updated nvm to v0.14.0
Remove Oracle JDK 7 installer cache entirely

Fixes https://github.com/travis-ci/travis-ci/issues/2738
Merge pull request #370 from GrahamCampbell/nvm

Updated nvm to v0.14.0