CI: New way to determnine libdir
We were using the presence of /usr/lib64 to determine where
shared libraries should be installed. This only existed on
Redhat based systems and was safe. If it existed, use it,
otherwise use /usr/lib.
Unfortunately, Ubuntu 19 decided to create a /usr/lib64 BUT
NOT INCLUDE IT IN THE DEFAULT ld.so.conf. So if anything is
installed there, it won't work.
The new method, just looks for $ID in /etc/os-release and if it's
centos or fedora, uses /usr/lib64 and if ubuntu, uses /usr/lib.
NOTE: This applies only to the CI scripts. Normal asterisk
build and install is not affected.
Change-Id: Iad66374b550fd89349bedbbf2b93f8edd195a7c3