This repository can no longer pass it's own .travis.yml 

#### Summary

While trying to create a PR for this repo it came to light the travis build for this repo at 92cad2c0ad2a347e2fff66e32f50d1c4b1f75b73 (at the time of this writing this is the HEAD) no longer passes Travis.

This is due to changes in required repositories and **composer** no longer supporting PHP 5.6.

https://travis-ci.com/laminas-api-tools/api-tools-doctrine/builds/151670014
