Rename PREFIX to BUILD_DIR in install script.
Rename PREFIX to BUILD_DIR in install script.

This is a more apropos name, since PREFIX doesn't actually get set until
the use of deploy.sh

rhelmer/socorro,KaiRo-at/socorro,mozilla/socorro,twobraids/socorro,spthaolt/socorro,Tchanders/socorro,twobraids/socorro,adngdb/socorro,KaiRo-at/socorro,pcabido/socorro,yglazko/socorro,Serg09/socorro,mozilla/socorro,m8ttyB/socorro,KaiRo-at/socorro,KaiRo-at/socorro,twobraids/socorro,luser/socorro,cliqz/socorro,luser/socorro,Serg09/socorro,spthaolt/socorro,AdrianGaudebert/socorro,rhelmer/socorro,pcabido/socorro,Serg09/socorro,yglazko/socorro,lonnen/socorro,lonnen/socorro,pcabido/socorro,luser/socorro,linearregression/socorro,cliqz/socorro,rhelmer/socorro,Serg09/socorro,AdrianGaudebert/socorro,cliqz/socorro,Tchanders/socorro,twobraids/socorro,Tchanders/socorro,m8ttyB/socorro,AdrianGaudebert/socorro,rhelmer/socorro,linearregression/socorro,linearregression/socorro,Serg09/socorro,adngdb/socorro,AdrianGaudebert/socorro,spthaolt/socorro,yglazko/socorro,Tayamarn/socorro,mozilla/socorro,m8ttyB/socorro,m8ttyB/socorro,AdrianGaudebert/socorro,KaiRo-at/socorro,spthaolt/socorro,Tayamarn/socorro,linearregression/socorro,Tchanders/socorro,luser/socorro,m8ttyB/socorro,m8ttyB/socorro,rhelmer/socorro,rhelmer/socorro,Tayamarn/socorro,yglazko/socorro,yglazko/socorro,cliqz/socorro,KaiRo-at/socorro,yglazko/socorro,pcabido/socorro,Tayamarn/socorro,spthaolt/socorro,twobraids/socorro,Serg09/socorro,pcabido/socorro,spthaolt/socorro,mozilla/socorro,Tayamarn/socorro,Tchanders/socorro,Tchanders/socorro,cliqz/socorro,luser/socorro,twobraids/socorro,lonnen/socorro,lonnen/socorro,linearregression/socorro,adngdb/socorro,AdrianGaudebert/socorro,luser/socorro,adngdb/socorro,mozilla/socorro,adngdb/socorro,cliqz/socorro,mozilla/socorro,pcabido/socorro,linearregression/socorro,Tayamarn/socorro,adngdb/socorro