tests/narrow-library.sh

dagutil: remove ability to invert instances

The previous commit removed the last consumer of this feature.

.. api:: remove inverse() methods from classes in dagutil

Differential Revision: https://phab.mercurial-scm.org/D4323

cat >> $HGRCPATH <<EOF
[extensions]
narrow=
[ui]
ssh=python "$TESTDIR/dummyssh"
[experimental]
changegroup3 = True
EOF