<?php

// Example of config file, add your own values here, all are imaginary

$config = array(

    'release_title'   => 'Freya',
    'release_version' => '0.3.2',

    'stripe_sk'        => 'sk_test_hoigesrjgoisrhgilgjrsfjs',
    'stripe_pk'        => 'pk_test_hoigesrjgoisrhgilgjrsfjs',

    'slack_token' => 'asdf-1234567890-7418529630-a7854123692-8412487519',

    'twitter_consumer_key'    => 'test_ckey',
    'twitter_consumer_secret' => 'test_csecret',
    'twitter_access_token'    => 'test_atoken',
    'twitter_access_secret'   => 'test_asecret',

    'sourceforge_iso_i386' => 'http://sourceforge.net/projects/elementaryos/files/stable/elementaryos-freya-i386.20150411.iso/download',
    'sourceforge_iso_amd64' => 'http://sourceforge.net/projects/elementaryos/files/stable/elementaryos-freya-amd64.20150411.iso/download',

);

<?php

// Example of config file, add your own values here, all are imaginary

$config = array(

    'release_title'   => 'Freya',
    'release_version' => '0.3.2',

    'stripe_sk'        => 'sk_test_hoigesrjgoisrhgilgjrsfjs',
    'stripe_pk'        => 'pk_test_hoigesrjgoisrhgilgjrsfjs',

    'slack_token' => 'asdf-1234567890-7418529630-a7854123692-8412487519',

    'twitter_consumer_key'    => 'test_ckey',
    'twitter_consumer_secret' => 'test_csecret',
    'twitter_access_token'    => 'test_atoken',
    'twitter_access_secret'   => 'test_asecret',

);

Remove unused variables from config.
Remove unused variables from config.