Yay, the first alpha of PostgreSQL 9.5 is out! This has lots of cool stuff in it, which you can read about elsewhere. What I'm posting here is a new experiment: offering up Docker images for testing the alphas and betas.
TL:DR = Image here, information and instructions on the wiki.
This occurred to me last week at DockerCon (naturally enough); one of the reasons more people don't test the PostgreSQL beta releases is that it can be a pain to install them, especially with all of the stuff you want to test. So I've just put a couple days' work into making it easier for you: all you gotta do is install the image and you can test away.
And, since you're testing in a container, you don't have to worry about messing up the PostgreSQL installation on the desktop/laptop/server you normally use. If you feel like doing your testing in a public cloud, many of them have ways to run containers as cloud servers, so that's easy to do.
I created this image crammed full of stuff: all of contrib, jsquery, pgxn, PL/python and PL/perl, a sample database, etc., so that you'd have something to test. I wasn't able to include PL/Lua due to build issues, nor PostGIS because I'm building from source, and building PostGIS from source is kinda scary. If you want to help me build a better test image, though, the Dockerfile project for it is here.
In the meantime, I've removed another excuse for not testing PostgreSQL 9.5. So what are you waiting for? Test already!