update setup.py to req. python-graph-core
update setup.py to req. python-graph-core

heuermh/gemini,xuzetan/gemini,bw2/gemini,brentp/gemini,bpow/gemini,arq5x/gemini,bpow/gemini,arq5x/gemini,bpow/gemini,bgruening/gemini,bw2/gemini,bgruening/gemini,bgruening/gemini,udp3f/gemini,udp3f/gemini,brentp/gemini,bgruening/gemini,arq5x/gemini,arq5x/gemini,xuzetan/gemini,brentp/gemini,udp3f/gemini,brentp/gemini,bw2/gemini,bw2/gemini,udp3f/gemini,bpow/gemini,xuzetan/gemini,heuermh/gemini,xuzetan/gemini,heuermh/gemini,heuermh/gemini