fix bug in version.py subprocess call
fix bug in version.py subprocess call

JuBra/cobrapy,jeicher/cobrapy,jerkos/cobrapy,zakandrewking/cobrapy,aebrahim/cobrapy,jeicher/cobrapy,aebrahim/cobrapy,zakandrewking/cobrapy,jerkos/cobrapy,JuBra/cobrapy