tests/narrow-library.sh

py3: convert strings to bytes in tests/test-remotefilelog-histpack.py

Differential Revision: https://phab.mercurial-scm.org/D5303

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