fix compilation on NERSC's edison machine using PrgEnv-intel

I had to make two minor modifications to Ray version 2.3.0 in order for
it to compile and install on NERSC's edison machine using PrgEnv-intel.
Below is the patch.

Signed-off-by: Rob Egan <rsegan@lbl.gov>
Link: http://permalink.gmane.org/gmane.science.biology.ray-genome-assembler/656
Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>