Add Sequra-Merchant-Id header

What's Changed

• Feature/PAR-571 Add Sequra-Merchant-Id header by @mescalantea in #4

New Contributors

• @mescalantea made their first contribution in #4

Full Changelog: 0.4.2...0.5.0

Form Deliveries

0.0.7

[FIX] Set type handling if rounding diff >0

PSR1/PSR2

• Don't break if without_tax values are not used
• Adopt PSR1/PSR2 code style

Added builder as template

0.0.2

[ADD] Builder and Helper improvements

First release

0.0.1

[chg] add keywords and fix license in composer.json