There's a setting on both travis and appveyor where you can mark certain entries in the build matrix as allowed failures. So they will run and you can look at the logs, but failing won't cause a red status. This is good for nightlies or when a package doesn't entirely support 32 bit, etc.
You should be changing the appveyor files in the same PR to add testing against 0.5 anyway. Same on Travis, "release" is going to change meaning so it's better to split entries for 0.4 and 0.5. What I'll do right now is replace the 0.5-latest downloads on s3 with rc1+1. That way Travis and Appveyor can have this bug fixed, but we're not making a new tag until more things are backported.
