Add support for MacOS

[vesavlad]

[rlepsch]

I tried to build it at MacOS, when I tried to run the last build ==>python setup.py build_ext --inplace

I got the error ==> Compiling src/pyosrm/core.pyx because it changed. [1/1] Cythonizing src/pyosrm/core.pyx running build_ext building 'pyosrm' extension creating build creating build/temp.macosx-10.9-x86_64-3.7 creating build/temp.macosx-10.9-x86_64-3.7/src creating build/temp.macosx-10.9-x86_64-3.7/src/pyosrm gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -arch x86_64 -g -I/usr/local/include/osrm -I/usr/include/boost -I/usr/local/include/boost -I/Library/Frameworks/Python.framework/Versions/3.7/include/python3.7m -c src/pyosrm/core.cpp -o build/temp.macosx-10.9-x86_64-3.7/src/pyosrm/core.o -std=c++14 src/pyosrm/core.cpp:681:10: fatal error: 'engine/api/base_result.hpp' file not found #include "engine/api/base_result.hpp" ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated.

And I found the "missing" file at ===> /Users/reinaldolepsch/pyosrm/osrm-backend/include/engine/api

I tried to modify setup.py and the PATH to include the path above, without success.