Use portable cmake system paths
Use portable cmake system paths

While Debian and derivatives put 64bit libraries (and pkgconfig files)
in `/usr/lib`, Fedora and derivatives put 64bit libraries in
`/usr/lib64`.

We add compatibility for both by using cmake's GNUInstallDirs set of
variables instead of hardcoded references to "lib" and "bin".

Copyright (c) 2019 DiGEiZ SAS.
Licensed under the terms of SimpleAmqpClient's MIT License

Signed-off-by: Julien DESMARAIS <168587e147dd73fed42478e2ce7b8a67e1cd31fb@digeiz.com>
Signed-off-by: Mickaël FALCK <2270856457c123a9a7378b875410731903942e62@digeiz.com>

alanxz/SimpleAmqpClient,alanxz/SimpleAmqpClient