bump to 1.15 and update pull
Merge pull request #33 from vieux/bump_1_15

bump to 1.15 and update pull
add size to list containers
Merge pull request #35 from ehazlett/list-container-size

add size to list containers
fix interface
Merge pull request #37 from vieux/fix_interfac

fix interface
add pause & unpause
Merge pull request #38 from vieux/pause_unpause

add pause & unpause
Add more options to Client.ContainerLogs call

Added `follow`, `timestamps`, `tail` options, according to
https://docs.docker.com/reference/api/docker_remote_api_v1.15/#get-container-logs

I know we're supposed to be on v1.10, but I tried using `stream` from
https://docs.docker.com/reference/api/docker_remote_api_v1.10/#attach-to-a-container
and it didn't work.

Signed-off-by: Donald Huang <don.hcd@gmail.com>
add ContainerLogs test