Upgrade ivy.api.reference version to 2.5.0
Upgrade ivy.api.reference version to 2.5.0

Contributed-by: Gintautas Grigelionis
Pull request: https://github.com/apache/ant-ivy/pull/90/

twogee/ant-ivy,apache/ant-ivy,apache/ant-ivy,twogee/ant-ivy,twogee/ant-ivy,twogee/ant-ivy,apache/ant-ivy,apache/ant-ivy