Problem/Motivation

After running a Composer install or update there is nothing in the command output to show what was changed (or not changed) by this installer plugin.

Expected behaviour

Composer will output the PHP CodeSniffer configuration key and value that it has set or changed.

Actual behaviour

Nothing is shown to even indicate whether this Composer Plugin for PHP CodeSniffer was executed or not. If a PHP CodeSniffer configuration is changed, Composer does not say so.

Steps to reproduce

1. Require this package with a supported standards package as per the README instructions.
2. Execute composer install or composer update

Proposed changes

Use the Composer IO to write to output:

1. Something to say the Plugin has started or is being run.
2. The config key and value to be set in PHP CodeSniffer.
3. (Optional) The results of the PHP CodeSniffer command to set a configuration key (ie. result from vendor/bin/phpcs --config-set key value)