gitifyhg blows up on HG 2.5.1

[Dusty Phillips]

Hi Max,

Can you update the travis build to include a build for 2.5.1. Everything
is passing on 2.5, but gitifyhg is exploding for all but 1 test when I
run it on 2.5.1. Horray for poorly designed, poorly documented, dare I
say idiotic unpublished APIs.

I am looking into this issue now.

Dusty

[Dusty Phillips]

Hmm, I lied. Apparently, gitifyhg only blows up when I have it installed
to system python via sudo pip install gitifyhg. When I have it running
in a virtualenv with hg 2.5.1, it works fine. This is rather mysterious.

Dusty

[Dusty Phillips]

By following a long and convoluted process that involved backing up my
entire site-packages directory, amoung other things, I determined that
the blow-uppiness was caused by having dulwich installed in my system
site packages. I can't imagine why that would cause grief, since I was
using the system git, but pip uninstall dulwich solved the problem.

I'll update the README.

Dusty