This update is to remove six support for dropping python2 from
heat-translator. Only the example of dockerfile is remained in which
it's expected libs are installed under `/usr/local/lib/python2.7`, so
it should also be considered to be updated later.
Signed-off-by: Yasufumi Ogawa <yasufum.o@gmail.com>
Change-Id: Iafbd1588674c95d6b6ec6b5429f2d34fb23081d0
4809045ed5