Revert "- upgrade to zeromq 3"
Revert "- upgrade to zeromq 3"

This reverts commit e348e1131a65dc15307b193185b1bd06fe441b19.

MichaelLiZhou/log-courier,dixitk13/log-courier,srizzling/log-courier,linearregression/log-courier,scrapinghub/log-courier,MichaelLiZhou/log-courier,scrapinghub/log-courier,linearregression/log-courier,srizzling/log-courier,srizzling/log-courier,linearregression/log-courier,MichaelLiZhou/log-courier,dixitk13/log-courier,scrapinghub/log-courier,dixitk13/log-courier