v1.8.0

ConstraintTrees v1.8.0

Diff since v1.7.0

Merged pull requests:

• generalize the carrier type of values (#54) (@exaexa)
• generalize the types in bounds (#55) (@stelmo)
• add pretty support for custom formatting of bound values (#56) (@exaexa)
• fix incorrect type instantiation (#57) (@stelmo)
• Finish up TODOs in QV types (#58) (@stelmo)
• Fix bug in drop_zeros (#60) (@stelmo)

Closed issues:

• comparison operators to create Constraints from Values? (#31)
• Automatic bound re-ordering, possibly a buggy fallback (#59)