/usr/lib/x86_64-linux-gnu/libsignon-glib.so is in libsignon-glib-dev 1.14+17.04.20161117-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libsignon-glib.so.1.0.0
/usr/lib/x86_64-linux-gnu/libsignon-glib.so.1.0.0