Update version on master

Signed-off-by: Joas Schilling <coding@schilljs.com>

appinfo/info.xml

@@ -14,7 +14,7 @@
 		More information is available in the Activity documentation.
 	</description>
 
-	<version>2.7.0</version>
+	<version>2.8.0</version>
 	<licence>agpl</licence>
 	<author>Frank Karlitschek</author>
 	<author>Joas Schilling</author>
@@ -36,7 +36,7 @@
 	<repository>https://github.com/nextcloud/activity.git</repository>
 
 	<dependencies>
-		<nextcloud min-version="14" max-version="14" />
+		<nextcloud min-version="15" max-version="15" />
 	</dependencies>
 
 	<background-jobs>