The images seem to have been broken starting with 12e12a39, but the
removal of Maven support from grpc-java also broke them further.

SSH handling no longer uses $HOME as it does not agree with /etc/passwd
in older docker versions[1] and prevented SSH from seeing the config
file.

Some effort was also made to reduce the image sizes by removing
temporary files.

1. https://github.com/docker/docker/issues/2968

refactoring will happen when the commands are final.

removing commented out line

- also corrects an error in the Go client test command

- the line that built and installed grpc ruby was mistakenly removed.

- necessary to allow seamless interop testing, as discussed earlier this week.

Adds a command for triggering a pull of the latest built docker images.
	Change on 2015/01/09 by temiola <temiola@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83641150