test: unset HGRCPATH

If HGRCPATH is set (to anything, including ''), only those paths are
searched, neglecting the usual locations like $HOME/.hgrc.  The gitifyhg
test suite creates $HOME/.hgrc.  Gitifyhg currently reads this file
manually (ignoring HGRCPATH), but remote-hg respects HGRCPATH.  This
commit explictly unsets HGRCPATH to prevent the user's environment from
affecting the test suite (e.g., 'alias.log = log --graph').

Discussed-with: Felipe Contreras <felipe.contreras@gmail.com>
test: fix end of lines

Somebody's text editor has been very naughty.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
test: trivial whitespace cleanups

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
test: simplification: use 'hg init hg_repo'

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
test: turn on debugging only when it can be used

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
test: fix 'push not create bookmark'

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>