v0.26

New features:

• Support the empty-cells attribute.
• Respect table, column and cell widths.

Bug fixes:

• #172:
  Unable to set table column width on tables td's.
• #151:
  Table background colour bleeds beyond table cell boundaries.
• #260:
  TypeError: unsupported operand type(s) for +: 'float' and 'str'.
• #288:
  Unwanted line-breaks in bold text.
• #286:
  AttributeError: 'Namespace' object has no attribute 'attachments'.