This reverts commit 79759fea, reversing
changes made to dc36f4df.

six is necessary for making these scripts cross compatible
between python 2.x and 3.x

Changes:
Add six to python_deps.include
Include python_deps.include to all Dockerfile templates in test directory
Include python_deps.include to all Dockerfile templates in stress_test directory
Include python_deps.include to all Dockerfile templates in interop_test directory
Replace print statements with print function calls (from futute..)
Replace .iteritems() with .items() wherever necessary
use six.moves to import BaseHTTPServer
Generate new dockerfiles using generate_projects.sh

SIGNIFICANTLY increases the performance of actually running tests...

There are cases where we truly don't care how long something takes, and
some external timeout will kill truly stuck processes, so let's
eliminate timeouts in those cases