Handle newline in ParseDpkgList

[DarthHater]

I wanted to improve the testapt.txt file so that it had a full list based on ubuntu:latest, and when I went to do it, I added a newline, and it blew up! This adds some logic to skip empty lines, improves the testapt.txt to be more reflective of a real OS scenario, and adds a couple more trace log statements for debugging

This pull request makes the following changes:

• Adds test case with newline in apt_test.go
• Adds logic in apt.go to skip empty lines
• Adds log statements in chase.go so that we see what's getting sent around at a trace level

cc @bhamail / @DarthHater

[zendern]

Closing since this was merged with #22