Added tag v1.2.0 for changeset 02dfe3df786a
Bump minor version, update history, remove old files
Update for Ruby 3, unhoe-ify, improve API docs
Fix the defaultdb build and use the sqlunet50 db for PostgresSQL testing.
Update data-dir calculation to use newer Rubygems API

Fixes #5.
Added tag v1.1.0 for changeset 3e0c43a8c8f0
Added signature for changeset b43660cdab72
Update history files
Update defaultdb build files
Simplified default DB code
Add a few more documentation fixes
Convert to modern symbol-hash syntax.
Update documentation
Update the wordnet-defaultdb gem to use the latest SqlUNet distro
Update my gem-signing cert
Update to WordNet 3.1, Sequel 5.0.

- Made tests run under both Sqlite and PG.
- Removed deprecated syntax/conventions from Sequel < 5
- Move to Ruby 2.4 as primary tested version, though 2.3 is
  still supported
- Made fetching Synset by ordinal deterministic
Update the README