Add environment variables for Gurobi optimizer

I have added the code below to my .bashrc file

    export GUROBI_HOME="/opt/gurobi600/linux64"
    export PATH="${PATH}:${GUROBI_HOME}/bin"
    export LD_LIBRARY_PATH="${GUROBI_HOME}/lib"

However, Emacs does not see this and thus I need to set them in Emacs
configuration using lisp functions.