This is because we build against a fixed PIL_INCLUDE_DIR whos version
needs to match the python version we install
Note: CI builds for windows use a hard-coded path for PIL. I manually
updated this to version 5.1.0
TODO@achin: automatically download the right version of pillow src
Note that at the moment, this is building and testing a "test" repo.
This test repo is not the same one that you use by following our docs.
Once this new code is better tested, we'll switch over (existing users
will not have to do anything to use this new repo).
Even though the overviewer repo is hosted on github, this new CI stuff
is useful for mirrors of overviewer hosted on gitlab.
To support package builds for a few distributions, a set of dockerfiles
have been created.
