A custom fork of the coenjacobs/mozart package is now used to change
the namespace of the appropriate packages (only league/container
for now) instead of the previously used prefix-vendor-namespaces script.
The packages are now moved to the src/Internal/Vendor namespace instead
of being modified in-place in the vendor directory. The namespaces
are thus now prefixed with Automattic\WooCommerce\Internal\Vendor
(previously it was just Automattic\WooCommerce\Vendor).
Nestor Soriano