Update library.properties - bump version to 1.1.15

Merge pull request #54 from tyeth/bump-version-2023-11-15-00-38-30

Update version number to 1.1.14

Merge pull request #53 from brentru/add-altitude

Add altitude sensor type

Bumped to 1.1.11

Update CI action versions

Bump to 1.1.9

Merge pull request #50 from brentru/add-more-units

Add sensor types for gas resistance and unitless percentage

Merge pull request #41 from tyeth/add-voc-nox-index

Adds NOx and VOC index to sensor types

Bump to 1.1.6

Bump to 1.1.5