/usr/lib/x86_64-linux-gnu/libUbuntuToolkit.so is in libubuntutoolkit5-gles-dev 1.3.1918+16.04.20160404-0ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libUbuntuToolkit.so.5.5.0