composer install fails on PHP 7.0

[simevo]

while setting up travis (#39) I stumbled upon this https://travis-ci.com/simevo/spid-wordpress/jobs/153619905

$ composer install --no-interaction
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.
  Problem 1
    - Installation request for doctrine/instantiator 1.1.0 -> satisfiable by doctrine/instantiator[1.1.0].
    - doctrine/instantiator 1.1.0 requires php ^7.1 -> your PHP version (7.0.25) does not satisfy that requirement.
  Problem 2
    - Installation request for myclabs/deep-copy 1.8.1 -> satisfiable by myclabs/deep-copy[1.8.1].
    - myclabs/deep-copy 1.8.1 requires php ^7.1 -> your PHP version (7.0.25) does not satisfy that requirement.
  Problem 3
    - doctrine/instantiator 1.1.0 requires php ^7.1 -> your PHP version (7.0.25) does not satisfy that requirement.
    - phpunit/phpunit-mock-objects 5.0.10 requires doctrine/instantiator ^1.0.5 -> satisfiable by doctrine/instantiator[1.1.0].
    - Installation request for phpunit/phpunit-mock-objects 5.0.10 -> satisfiable by phpunit/phpunit-mock-objects[5.0.10].

[michaeltieso]

Is this still showing up as an issue for you?

[simevo]

since you merged PR #43 it's now reported by Travis for master as well: https://travis-ci.com/simevo/spid-wordpress/jobs/153789100

[simevo]

this happens when one performs composer require .. or composer update on a system which runs PHP 7.1 or later, and then commits the composer.lock file; I normally use a container with debian stretch (our standard development environment) to run these commands, them commit the resulting composer.lock

[michaeltieso]

I see. Why is Travis being used for this? This is only for development, not pushing to live. Your PHP version is irreverent for building.