Add changelog.

Signed-off-by: crynobone <crynobone@gmail.com>
Add NotifiableInterface.

Signed-off-by: crynobone <crynobone@gmail.com>
Add additional files to export-ignore.

Signed-off-by: crynobone <crynobone@gmail.com>
Orchestra\Notifier\NotifierInterface should utilize Orchestra\Notifier\NotifiableInterface.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.1'