Dockerfile to run test (just an example, don't merge)

[yanhick]

@EBatTiVo,
if you want to try it, here is the short version:
Assuming that you have docker installed, run the following commands:

docker build -t intellij-haxe-test .

This will use the Dockerfile to build an image containing all the build tools and IDEA SDKs. You only need to do it once.
Now, everytime you want to run the tests do:

docker run -v ${PWD}:/intellij-haxe -t intellij-haxe-test

This will mount your code folder in /intellij-haxe in the container and run make test (the default command, specified in the Dockerfile).
By default it will test IDEA 13.1.6, if you want to test another version you can pass env variables when running the container. For example for 14.0.1, you'll do:

docker run -e "IDEA_VERSION=14.0.1" -v ${PWD}:/intellij-haxe -t intellij-haxe-test