This commit does several cleanups to the Dockerfiles that we have:
* git is removed from the images after Kuryr packages installation
* jq and wget is removed from kuryr-cni image as those ar no longer used
* explicit setuptools installation is no longer required
* raw Kuryr code is removed from images after it's `pip install`ed
* unnecessary VOLUME line is removed from kuryr-cni Dockerfile
* CNI_CONFIG_DIR and CNI_BIN_DIR build arguments are removed from
kuryr-cni Dockerfile as they are not used anywhere. Initially we've
kept them to allow deployer to tell where host's /etc/cni/net.d and
/opt/cni/bin will be mounted, but one of the refactorings of
cni_ds_init must have stopped depending on them and we simply started
to expect the mounts to be in the same paths as on host. We can
continue to do that.
The build_cni_daemonset_image script was created back in the time when
we have had multi-stage build of the kuryr-cni image. This is no longer
the case and building the image is as easy as:
`docker build -f cni.Dockerfile .`
Given that this commit removes the script and updates documentation to
recommend using `docker build` directly.
Change-Id: Ib1807344ede11ec6845e5f09c5a87c29a779af03
8b76509514