Need to update alchemy/zippy

[mike-potter]

The composer.json currently has:

    "alchemy/zippy": "^0.3",

However, the latest D8 drupal/console has:

     "alchemy/zippy": "0.4.3",

While I have an issue with drupal/console specifying such a specific version, this is a major issue that prevents us from using a single vendor and composer.json for a D8 project that includes pattern-lab.

Proposal

Update patternlab-php-core to use:

    "alchemy/zippy": "~0.3",

which doesn't have the same restriction as ^0.3 when working with versions less than 1.0 (I believe).

(From composer docs here https://getcomposer.org/doc/articles/versions.md#caret-version-range- is says "For pre-1.0 versions it also acts with safety in mind and treats ^0.3 as >=0.3.0 <0.4.0". No similar comment for the ~ operator)