Minor release bump

We're proud to announce a new minor release including Cypress v4 support.

The following features and bugfix are included in this release:

• Add promotion fixture
• Update dependency for actual cypress@^4.0.0
• Update documentation reference
• Add order fixture which uses a logged-in customer
• Adds new storefront commands and rearrange existing ones
• Re-integrate cypress-log-to-output plugin
• Fix incorrect fixture reference
• Update readme for general commands
• Change authentication storage from localStorage to Cookie