Makefile gcc6 for MAC about bart

[jtamir]

You are right. In the meantime, you can make a Makefile.local file with the line CC=gcc-mp-6

[JE-Jimenez]

I also notice that when you do type: $ make install macOS won't allow you to save in /usr/bin, therefor it would be convenient if you add a option for Mac in the Makefile: e.g.

ifeq ($(BUILDTYPE), MacOSX)
         PREFIX ?= usr/local	
else
	PREFIX ?= usr/
endif

As you pointed out, I fixed this issue within the Makefile.local. if you install using brew then you don't need to worry about it. Well, I hope this comments are helpful. Thank very much for maintaining this AMAZING library.