Test adaptations for Heptapod 0.26
Probably because of hg 5.9 vs 5.7, the remote:
prefix can be
farther from the expected environment out.
Also, the HEPTAPOD_NO_GIT
environment variable now appears.
It would be dubious to assert it, and it's better anyway
to assert each variable independently, although it is true
that improving the test with variables that we don't want
to be available to hooks would be better.