Use source instead of bash to launch lesson 15 generators script
Use source instead of bash to launch lesson 15 generators script

on os x, invoking bash no longer seems to inherit the DYLD_LIBRARY_PATH
environment var


Former-commit-id: 59f07ae9fe15613389afc51bb384896b84000c33
darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide