Now that we added morx support, our OS X bot is running them through CoreText
and failing (with a DoS / infinite loop no less!).  Always run tests through
our own shaper.

Fixes https://github.com/harfbuzz/harfbuzz/issues/1212

Decode the string as Python 3 returns bytes string, and also don’t
assume that it ends with a new line.

https://gitlab.kitware.com/cmake/cmake/issues/17630

Always pass hb-shape as first argument to run-tests.py.

Also require automake 1.13.

In anticipation of importing more test suites.