Update buildbot.sh
Update buildbot.sh

Fixes issue #300 - buildbot script exits with 1 on git pull failure.
CoolProp/CoolProp,JonWel/CoolProp,DANA-Laboratory/CoolProp,JonWel/CoolProp,CoolProp/CoolProp,dcprojects/CoolProp,CoolProp/CoolProp,dcprojects/CoolProp,JonWel/CoolProp,dcprojects/CoolProp,JonWel/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,DANA-Laboratory/CoolProp,dcprojects/CoolProp,JonWel/CoolProp,henningjp/CoolProp,dcprojects/CoolProp,henningjp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,JonWel/CoolProp,henningjp/CoolProp,henningjp/CoolProp,DANA-Laboratory/CoolProp,CoolProp/CoolProp,dcprojects/CoolProp,DANA-Laboratory/CoolProp,DANA-Laboratory/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,CoolProp/CoolProp,dcprojects/CoolProp,henningjp/CoolProp,henningjp/CoolProp,JonWel/CoolProp