Log Message:
textproc/libxlsxwriter: update to 0.8.7

Release notes:
 - Added support for adding VBA macros to workbooks. These macros can
   be extracted from existing xlsm files, created in Excel, and added to
   new xlsm files.
 - Added support for ZIP64 extensions when writing very large xlsx
   files to allow the zip container, or individual XML files within it,
   to be greater than 4 GB.
 - Added extra validity checks on worksheet names.