Travis CI pipeline is broken for PHP 5.3

[mdupont]

Describe the Bug

When running the Travis CI job for PHP 5.3 under Ubuntu Precise, it crashes during the before_install step, when running apt-get update.

It is because Ubuntu Precise (12.04) is EOL for a long time and the MongoDB repo is not available anymore. However Ubuntu 12.04 is the only one where PHP 5.3 can still run.

BTW is it still worth supporting PHP 5.3? Also, since Precise is EOL it is likely that more and more breakages will occur, would it be worth switching to Xenial (default in Travis), at least for the PHP versions that it supports (5.6+)?

If it makes past this step, it then crashes at composer install --prefer-source because of exceeded memory usage, 2G is no longer enough it seems.

Steps to Reproduce

• Open a PR
• Look at Travis CI log for PHP 5.3

Expected Behavior

The build should complete.

Current Behavior

The build crashes during the operation sudo apt-get update -qq with the error message "E: Failed to fetch http:https://downloads-distro.mongodb.org/repo/debian-sysvinit/dists/dist/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)"

Once fixed, it then crashes during composer install --prefer-source with the message "PHP Fatal error: Allowed memory size of 2147483648 bytes exhausted (tried to allocate 32 bytes)"

Context

• PHP Version: 5.3
• PHPWord Version: any

[0b10011]

It should be noted that #1669 requires a bump to 7.0 at least, so this is yet another reason to bump the minimum.