Remove --kill option

It's better to stop the containers, so in order to keep Crane
simple, I think it's best to remove the --kill option.
Allow to specify default group
A little ugly; but you can specify -n to specify no-cache.

Signed-off-by: Scott M. Likens <scott@likens.us>
Revert "Remove --kill option"

This reverts commit bbc15bf1bb23b042bc4de88862dd4fc585514d52.

Conflicts:
	cmd.go
	containers.go
Add basic support for pushing images
Format source code
Remove the force flag
  Add a rebuild flag; make it available during `run`, `lift` and it should be default during provision.

We always build the image if specified to build and assume the local image is out of date.

Signed-off-by: Scott M. Likens <scott@likens.us>
make rebuild the first option in lift
Right there is no rebuild here https://github.com/michaelsauter/crane/pull/40#discussion-diff-13580346R288

Let's actually make it work too.

Signed-off-by: Scott M. Likens <scott@likens.us>
right it should kill the container if it's rebuilding

Signed-off-by: Scott M. Likens <scott@likens.us>
  - Add the ability to get logs
  Remove fmt, it's not used
  Rename lift to run; cleaned up a bit of funk.

Signed-off-by: Scott M. Likens <scott@likens.us>