Fix ES8 incompatibility

Remove _doc from URLs except PUT url for posting items

Fixup changelog, version.rb, and gemspec

- Changelog: unreleased to v0.2.0 and update compare URL
- Update version.rb to 0.2.0
- Add Will to authors

take v0.2.0 out of beta, with latest updates

Merge pull request #172 from CDRH/feature/fields

Feature/fields

updates changelog

Merge pull request #158 from CDRH/dev

hotfix/vra_to_solr_fields

Merge pull request #151 from CDRH/pb

Pb

adds links to changelog

version bump

version bump