1.1.0

This is a minor release with a few new features from libsemigroups_ and some bugfixes:

• Throw if bad alphabet or rules by @james-d-mitchell in #317
• Add some missing and features from the presentation namespace by @james-d-mitchell in #318
• Test default values and datetime types by @Joseph-Edwards in #324
• Todd coxeter additions by @james-d-mitchell in #328