Add eos library target to fit-model-simple
Add eos library target to fit-model-simple

Also move adding -pthreads to examples/CMakeLists.txt, this will eventually have to be modernised as well

patrikhuber/eos,icyrizard/eos,icyrizard/eos,patrikhuber/eos,icyrizard/eos,patrikhuber/eos