Add unreleased 8.0 entry to CHANGELOG

CHANGELOG

+v8.0.0 (unreleased)
+
 v7.14.1
   - Fix skipped svg
@@ -298,4 +300,4 @@ v1.2.0
 v1.1.0
   - Added JSON response for builds status
-  - Compatible with GitLab v4.0.0
\ No newline at end of file
+  - Compatible with GitLab v4.0.0