0.4.0

fetch_screenshots

• Add a user agent to requests made to Treeherder's API (@edmorley)
• Update artifact URL after bug 1270629
• Use TaskCluster to find nightly revisions

compare_screenshots

• Improve system UI cropping
• Add mitigation for CVE-2016–3714
• Handle job name prefixes
• Use the last matching after directory for comparisons
• Support comparing images with and without the test file name to each other
• Support passing arguments directly to cli()
• Don't fail removing intermediate images if they don't exist