Bump version to 1.7.0

Bump version to 1.6.1

Update image source in README.md

Merge pull request #23 from john-k-mcdowell/feature/data-age-sensor

Add Data Age sensor to track time since last BLE update

Bump version from 1.4.1 to 1.4.2

fix version

Update README with Type C product information

Added Type C section with product description and image.

Remove Last Update sensor

Fix issue with reboot

Persist values on reboot #14