Merge fix for IVY-1399 from master.

Merging: https://github.com/apache/ant-ivy/commit/c66b23747627a2b432e0068561d457cab9f97ead

Backported/fixed tests for Ivy 2.3.x differences.
Add travis yml for validation of pull requests.
Fix travis yml for testing.
Disable test using old infrastructure which no longer exists.
Merge pull request #12 from sbt/wip/backport-conflict-issue-fix

Wip/backport conflict issue fix