Looking at the check failures, it doesn't seem they were caused by this particular change.
e.g.
com.github.dockerjava.api.DockerClientException: Could not push image: Error pushing to registry: Authentication is required.

No worries about the failing tests. But I would like to ask for a test case for your PR.

absolutely, I don't know why the I didn't find the existing LogContainerCmdImplTest before I submitted this PR...

Added the test, here is the output from the test when I run the test locally:

23:15:35.288 DEBUG c.g.d.jaxrs.DockerCmdExecFactoryImpl - 19 * Sending client request on thread pool-72-thread-1
19 > GET https://192.168.99.100:2376/containers/2db7dc40e772de71a074153124b8c163411e0c603963f828d0d4d29f8fe40c87/logs?timestamps=0&stdout=1&stderr=1&follow=0&since=1441952195&tail=all

23:15:35.289 DEBUG o.a.h.i.c.PoolingHttpClientConnectionManager - Connection request: [route: {s}->https://192.168.99.100:2376][total kept alive: 2; route allocated: 2 of 2; total allocated: 2 of 20]
23:15:35.289 DEBUG o.a.h.i.c.DefaultManagedHttpClientConnection - http-outgoing-285: Close connection
23:15:35.289 DEBUG o.a.h.i.c.PoolingHttpClientConnectionManager - Connection leased: [id: 287][route: {s}->https://192.168.99.100:2376][total kept alive: 1; route allocated: 2 of 2; total allocated: 2 of 20]
23:15:35.339 DEBUG o.a.h.i.c.PoolingHttpClientConnectionManager - Connection [id: 287][route: {s}->https://192.168.99.100:2376][state: O=yongxing] can be kept alive indefinitely
23:15:35.339 DEBUG o.a.h.i.c.PoolingHttpClientConnectionManager - Connection released: [id: 287][route: {s}->https://192.168.99.100:2376][state: O=yongxing][total kept alive: 2; route allocated: 2 of 2; total allocated: 2 of 20]
23:15:35.339 DEBUG c.g.d.jaxrs.DockerCmdExecFactoryImpl - 20 * Client response received on thread pool-72-thread-1
20 < 200
20 < Content-Length: -1
20 < Content-Type: application/json; charset=utf-8

Seems like "since" field is introduced in the remote API 1.19.
https://docs.docker.com/reference/api/docker_remote_api_v1.19/#get-container-logs

I didn't find the "since" in API 1.18
https://docs.docker.com/reference/api/docker_remote_api_v1.18/#get-container-logs

The test for "since" pass on my local machine, where it has:
{"Version":"1.8.1","ApiVersion":"1.20","GitCommit":"d12ea79","GoVersion":"go1.4.2","Os":"linux","Arch":"amd64","KernelVersion":"4.0.9-boot2docker","BuildTime":"Thu Aug 13 02:49:29 UTC 2015"}

For the failed test on ci/circleci, it has:
{"ApiVersion":"1.18","Arch":"amd64","GitCommit":"2f3236d","GoVersion":"go1.4.2","KernelVersion":"3.13.0-61-generic","Os":"linux","Version":"1.6.2-circleci"}

The API version difference explains why. Also worth mentioning that adding the since field is a no-op for apiVersion < 1.19.

How do you suggest handling the dependency?

As stated in the README.md the current docker-java release version supports docker remote API > v1.19, so this will be no problem. As CircleCI uses a quite old docker version I will disable it soon.

Great! Let me know if there is anything else I need to do to get it to a mergable state from your point of view.

Thanks for your contribution!