Bump minimum Mocha version to >= 1.4.0
Bump minimum Mocha version to >= 1.4.0

This is necessary due using `mocha/minitest` instead of `mocha/setup`.

The minitest require was introduced in Mocha 1.0.0 but was previously
named `mocha/mini_test` (with an underscore). It was renamed in 1.4.0.

Shopify/shopify_api