We want to default to running all tox environments under python 3, so
set the basepython value in each environment.
We do not want to specify a minor version number, because we do not
want to have to update the file every time we upgrade python.
We do not want to set the override once in testenv, because that
breaks the more specific versions used in default environments like
py35 and py36.
Change-Id: I7c221de42f30e6ef52f32b5ccd0905859d027c07
Signed-off-by: Doug Hellmann <doug@doughellmann.com>
Set the default python to python3 except for the py27 environment. We
have to set that explicitly to override the new default.
Change-Id: Iff0bb093eb69a426d623d97b0338ff19f41f1e3c
Signed-off-by: Doug Hellmann <doug@doughellmann.com>