Change the directory inside of tgz files.

Currently the directory inside of the tgz files is /usr/local/bin
and this is causing some confusion, and problems with people who already
have stuff in those directories. This commit changes the directory
to /docker to help remove the confusion.

Signed-off-by: Ken Cochrane <kencochrane@gmail.com>
(cherry picked from commit 7df5b32834237eac4c338f0ce1cba65b86bbe642)