Update INSTALL.md
Update INSTALL.md

Former-commit-id: 38487b634d21e1779b2fef80a41fdc55121f51e1
clab/cnn,chunyang-wen/dynet,shuheik/dynet,shuheik/dynet,xunzhang/dynet,chunyang-wen/dynet,danielhers/dynet,shuheik/dynet,clab/dynet,clab/dynet,chunyang-wen/dynet,clab/cnn,danielhers/dynet,danielhers/dynet,clab/dynet,danielhers/dynet,clab/cnn,shuheik/dynet,danielhers/dynet,shuheik/dynet,danielhers/dynet,shuheik/dynet,chunyang-wen/dynet,clab/dynet,clab/dynet,clab/dynet,shuheik/dynet,xunzhang/dynet,danielhers/dynet,clab/dynet,xunzhang/dynet,xunzhang/dynet