check git version requirements

This allows v1 tests to continue working on git 1.8.0 for
now.  This allows git 2.1.4 packaged with Debian 8 ("jessie")
to run old tests, at least.

I suppose it's safe to drop Debian 7 ("wheezy") due to our
dependency on git 1.8.0 for "merge-base --is-ancestor".

Writing V2 repositories requires git 2.6 for "get-mark"
support, so mask out tests for older gits.

1 files changed, 2 insertions, 0 deletions

diff --git a/t/psgi_v2.t b/t/psgi_v2.t
index 65448dc4..98112494 100644
--- a/t/psgi_v2.t
+++ b/t/psgi_v2.t
@@ -3,6 +3,8 @@
 use strict;
 use warnings;
 use Test::More;
+require './t/common.perl';
+require_git(2.6);
 use File::Temp qw/tempdir/;
 use PublicInbox::MIME;
 use PublicInbox::Config;