Static cache expiry config key is wrong

[jasonvarga]

Bug Description

You should be able to define the expiry as explained in the docs. Currently it uses what looks like a ported v2 version.

This needs to be backwards compatible, since users may have worked out that you can define default_cache_length. (We should check for expiry and default_cache_length).

Extra Detail

statamic/docs#294

Environment

Statamic version: 3.0.20

[jelleroorda]

Would it be an idea to change this to "default" laravel behaviour as well, by choosing an expiry in seconds instead of minutes?

[okologisk]

After updating to 3.0.38, it looks like cache is not cleared - even when clearing via CP.

`'strategies' => [

    'half' => [
        'driver' => 'application',
        'expiry' => 5,
    ],

    'full' => [
        'driver' => 'file',
        'path' => public_path('static'),
        'lock_hold_length' => 0,
    ],

],

`

[jasonvarga]

Provide some more details in a separate issue please.