py3: use range instead of xrange on py3 in tests/test-filecache.py
xrange is not present on py3.
Differential Revision: https://phab.mercurial-scm.org/D2324
py3: use range instead on xrange on py3 in tests/test-atomictempfile.py
xrange is not available on Python 3.
Differential Revision: https://phab.mercurial-scm.org/D2323