D2132: py3: replace file() with open() in test-convert-hg-source.t

[yuja (Yuya Nishihara)]

yuja requested changes to this revision.
yuja added a comment.
This revision now requires changes to proceed.


  Needs b''.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D2132

To: pulkit, #hg-reviewers, yuja
Cc: yuja, mercurial-devel