SDC-5231: update dependency checker script to work on python3
SDC-5231: update dependency checker script to work on python3

Change-Id: I9eda0b8337842bd8d3d43d3b4589b4c77071d642
Reviewed-on: https://review.streamsets.net/6442
Tested-by: StreamSets CI <809627f37325a679986bd660c7713476a56d59cd@streamsets.com>
Reviewed-by: Dima Spivak <bed3f98d0a894717be46c58ffa90302af9946688@streamsets.com>

streamsets/datacollector,streamsets/datacollector,rockmkd/datacollector,SandishKumarHN/datacollector,rockmkd/datacollector,streamsets/datacollector,z123/datacollector,z123/datacollector,z123/datacollector,streamsets/datacollector,z123/datacollector,kunickiaj/datacollector,rockmkd/datacollector,rockmkd/datacollector,kunickiaj/datacollector,streamsets/datacollector,rockmkd/datacollector,kunickiaj/datacollector,SandishKumarHN/datacollector,kunickiaj/datacollector,z123/datacollector,SandishKumarHN/datacollector,SandishKumarHN/datacollector,SandishKumarHN/datacollector,kunickiaj/datacollector