adding build to gitignore
adding build to gitignore

Foxboron/hy,kirbyfan64/hy,freezas/hy,larme/hy,tianon/hy,jakirkham/hy,kartikm/hy,zackmdavis/hy,algernon/hy,adamfeuer/hy,michel-slm/hy,farhaven/hy,aisk/hy,aisk/hy,timmartin/hy,tianon/hy,ALSchwalm/hy,farhaven/hy,paultag/hy,larme/hy,gilch/hy,tianon/hy,tuturto/hy,kirbyfan64/hy,farhaven/hy,Tritlo/hy,mtmiller/hy,hcarvalhoalves/hy,larme/hy,Foxboron/hy,hcarvalhoalves/hy,aisk/hy