Update to 0.5.6

• Add LICENSE_FILE
• Add NO_ARCH
• Allow concurrent installation (USE_PYTHON=concurrent)
• Add DOCS and MIGRATIONS options

Changes: https://github.com/mbi/django-simple-captcha/blob/master/CHANGES
PR: 228133
Submitted by: Kai <freebsd_ports@k-worx.org>
Approved by: John Hixson <jhixson@gmail.com> (maintainer)