Add Python 3.5 classifier and venv
Add Python 3.5 classifier and venv

Now that is a passing gate job,we can claim support for
Python 3.5 in the classifier,This patch also adds the
convenience py35 venv.

Change-Id: I2b786d51ce4f276d465f7b12b5da53aa7df64287

dtroyer/osc-lib