Installing pytest through pip3 (at least sometimes) doesn't create a script.
This means calling `which` won't work.
Changed configure so that it can also test if the module is present by calling python/python3.
Change the error message for when pytest can't be found, so that it's clear to the user `configure` must be ran again after installing pytest.
Addresses #486 and takes into account @rustyrussell 's
comment about PYTEST defined in the environment which
always overrides without checking the version.
You can use environment variables or the commandline to set defaults.
It looks very autoconf, but you don't need to learn m4.
Doesn't cover all the obscure flags, but it's easy to extend.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell
lucash-dev
Jan Sarenik
Christian Decker