v0.6.0

Features

• Added Expenses without invoice submission (06f0314)
• Added lastInvoiceNumber attribute to expense invoices Header (ff3b7d3)
• Juridic and physical person expenses with invoices registration working (2b15960)

Bug Fixes

• Greek VIES code uses ISO 639-1 language code (EL) instead of ISO 3166 country code. (185ad57), closes #48
• Loading international invoices from XML was not loading proper recipient identifier data (7b45e6e), closes #47