Add cacheFrom to build options

[thomaschaaf]

This adds the cache-from build option (moby/moby#26839) and fixes #1382.

[thomaschaaf]

Is there a problem with my addtion?

[graingert]

@shin- ping

[bfirsh]

LGTM!

A nit: the cachefrom option also needs to be added to the ImageCollection docstring.

(@shin- perhaps we should add a comment to duped docstrings like this to remind contributors to copy changes between them.)

[graingert]

@thomaschaaf can you update the ImageCollection docstring?

[MichaelPereira]

@thomaschaaf To save you the search, this is where it should be added:

docker-py/docker/models/images.py

Lines 111 to 142 in bb66525

	path (str): Path to the directory containing the Dockerfile
	fileobj: A file object to use as the Dockerfile. (Or a file-like
	object)
	tag (str): A tag to add to the final image
	quiet (bool): Whether to return the status
	nocache (bool): Don't use the cache when set to ``True``
	rm (bool): Remove intermediate containers. The ``docker build``
	command now defaults to ``--rm=true``, but we have kept the old
	default of `False` to preserve backward compatibility
	stream (bool): *Deprecated for API version > 1.8 (always True)*.
	Return a blocking generator you can iterate over to retrieve
	build output as it happens
	timeout (int): HTTP timeout
	custom_context (bool): Optional if using ``fileobj``
	encoding (str): The encoding for a stream. Set to ``gzip`` for
	compressing
	pull (bool): Downloads any updates to the FROM image in Dockerfiles
	forcerm (bool): Always remove intermediate containers, even after
	unsuccessful builds
	dockerfile (str): path within the build context to the Dockerfile
	buildargs (dict): A dictionary of build arguments
	container_limits (dict): A dictionary of limits applied to each
	container created by the build process. Valid keys:
	- memory (int): set memory limit for build
	- memswap (int): Total memory (memory + swap), -1 to disable
	swap
	- cpushares (int): CPU shares (relative weight)
	- cpusetcpus (str): CPUs in which to allow execution, e.g.,
	``"0-3"``, ``"0,1"``
	decode (bool): If set to ``True``, the returned stream will be
	decoded into dicts on the fly. Default ``False``.

[graingert]

@thomaschaaf @MichaelPereira I've got a fork of this at #1417 with that change.

[shin-]

Closing: #1417