Version 0.8.0

Changed

• Updated relationships document with more examples regarding
  multiple foreign key declarations.

Added

• contains method to queryset allowing to query if a given model or reflected model exists in the
  queryset.
• related_name is now supported on ForeignKey allowing transverse queries.
• Allow reverse queries using nested fields.
• on_update for ForeignKey and OneToOne fields
• Multiple ForeignKeys to the same table is now possible.
• Related Name document added
• Nested queries using related_name