tests/test-issue1089.t

contrib: install latest versions of Python

Let's keep our build environment modern.

We upgrade 3.5-3.8 on Linux. Just 3.7 and 3.8 on Windows because we
don't use <3.7 on Windows.

Differential Revision: https://phab.mercurial-scm.org/D9145

https://bz.mercurial-scm.org/1089

  $ hg init
  $ mkdir a
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b
  $ hg ci -m m a

  $ mkdir a b
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b
  $ cd b

Relative delete:

  $ hg ci -m m ../a

  $ cd ..