Merge 208 broke build with gcc-7.x

@riccardo-sturani Looks like !208 (merged), for #14 (closed), has broken the build:

In file included from LALSimNeutronStarEOS.c:101:0:
LALSimNeutronStarEOSPiecewisePolytrope.c: In function 'XLALSimNeutronStarEOS4ParameterPiecewisePolytrope':
LALSimNeutronStarEOSPiecewisePolytrope.c:485:8: error: ',Gam3=' directive output truncated writing 6 bytes into a region of size 0 [-Werror=format-truncation=]
     if(snprintf(eos->name, sizeof(eos->name), "4-Piece Polytrope (p1=10^%.2f Pa,Gam1=%10.2e,Gam2=%10.2e,Gam3=%10.2e)", logp1_si, gamma1, gamma2, gamma3) >= (int) sizeof(eos->name))
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
LALSimNeutronStarEOSPiecewisePolytrope.c:485:8: note: 'snprintf' output between 82 and 391 bytes into a destination of size 64

This is causing the build to fail on Debian Buster and Ubuntu Artful, specifically platforms that using gcc-7.x. Can you please address this ASAP as I'm trying to get some other changes in related to these platforms and this build error is preventing me from doing so.