force installation of libgmp in travis
force installation of libgmp in travis

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