Fixes installer script to work with bash 3
Fixes installer script to work with bash 3

which is the builtin version on Mac OS X. (Fixes #352)

It turns out source with process substitution didn't work in the old days.

HazyResearch/deepdive,zifeishan/deepdive,maalmeida1837/deepdive,shahin/deepdive,closedLoop/deepdive,HazyResearch/deepdive,nvoron23/deepdive,closedLoop/deepdive,closedLoop/deepdive,Atlas7/deepdive,RTsWorld/deepdive,kod3r/deepdive,wgapl/deepdive,Atlas7/deepdive,kod3r/deepdive,sai16vicky/deepdive,nvoron23/deepdive,RTsWorld/deepdive,nvoron23/deepdive,shahin/deepdive,sky-xu/deepdive,vasyvas/deepdive,Gela/deepdive,nvoron23/deepdive,vsoch/deepdive,Atlas7/deepdive,kod3r/deepdive,HazyResearch/deepdive,vsoch/deepdive,wgapl/deepdive,kod3r/deepdive,Gela/deepdive,maalmeida1837/deepdive,maalmeida1837/deepdive,vasyvas/deepdive,HazyResearch/deepdive,AlexisBRENON/deepdive,Gela/deepdive,sai16vicky/deepdive,Gela/deepdive,AlexisBRENON/deepdive,AlexisBRENON/deepdive,vsoch/deepdive,sky-xu/deepdive,AlexisBRENON/deepdive,maalmeida1837/deepdive,Gela/deepdive,RTsWorld/deepdive,Atlas7/deepdive,vasyvas/deepdive,topojoy/deepdive,vsoch/deepdive,maalmeida1837/deepdive,Atlas7/deepdive,zifeishan/deepdive,zifeishan/deepdive,closedLoop/deepdive,sai16vicky/deepdive,wgapl/deepdive,nvoron23/deepdive,sai16vicky/deepdive,closedLoop/deepdive,kod3r/deepdive,RTsWorld/deepdive,vsoch/deepdive,wgapl/deepdive,topojoy/deepdive,topojoy/deepdive,wgapl/deepdive,topojoy/deepdive,zifeishan/deepdive,vasyvas/deepdive,RTsWorld/deepdive,topojoy/deepdive,vasyvas/deepdive,sai16vicky/deepdive,zifeishan/deepdive,AlexisBRENON/deepdive