options.PouchDB

[gr2m]

closes #104

Progress

• [x] https://github.com/hoodiehq/pouchdb-hoodie-sync/pull/83
• [x] https://github.com/hoodiehq/hoodie-store-client/pull/137
• [x] update package.json
• [x] test with hoodie-app-tracker`s e2e tests

[gr2m]

this is ready for review @hoodiehq/maintainers @inator 👀