Merge pull request sabre-io#1024 from ByteHamster/release-080

Bumped version to 0.8.0

Bumped version to 0.7.2

Bumped version to 0.7.1

Updated changelog for 0.7.0

Bumped version to 0.6.1

Fixed invite sender address

Otherwise, fresh installations use
`From:  <noreply@$_SERVER[SERVER_NAME]>`

Bumped version to 0.5.3

Bumped version to 0.5.2

Merge pull request sabre-io#778 from ByteHamster/update-url

Updated project page url

Set release date.