start the migration to shapeless 2.0
merge cons renaming and shapeless 2.0 migration
try whether you can do shapeless 2.0 records with type sets. You can

incredibly messy code, but it works.
explain some funky ideas about this to @laughedelic
some real funky stuff :)
try to split ops into api and impl: failed, clean up a bit
think about how to avoid refinements, minor edits
* Moved ops to a separate folder;
* Added Pop which is the same as Lookup, but removes the element from the set;
* Added Choose which chooses (projects) a subset of a given type;
* Added Reorder which is same as Choose, but for equivalent sets;
* Renamed Union and Subtract;
* Union unicode symbol (\cup);
* Added tests;
Reviewing this code; planning refactoring/reorg between different libs
Added construction for bounding type-set by a type-union (every element is one of ...)
Merge branch 'experiment/records' of github.com:ohnosequences/type-sets into experiment/records
Merge branch 'master' into experiment/records
Merge branch 'master' into experiment/records
Merge branch 'feature/ops/more-cool-ops' into experiment/records
initial record and props impl migrated from scarph and tabula
add value type extractor to Property
finish with records, some renaming and aliasing
fix a lot of things, do some stuff pfff
Fixes related to the empty set to pass tests
Added release notes