v0.4.0

This release reduces the chances of duplicate jobs from the same source and provides the ability to resubmit cancelled or deleted jobs.

What's Changed

• Tooling updates (Python, Django, Wagtail versions), coverage summary and CI fixes by @zerolab in #21 and #24
• Unique jobs by @zerolab in #27
• Resubmit cancelled/deleted jobs by @zerolab in #29
• Preparing 0.4.0 release by @stevejalim in #30

Full Changelog: v0.3.0...v0.4.0