0.3.0

This is the 0.3.0 release of Helios. Helios is getting more and more fleshed out as we are approaching the 1.0 release cycle.

As we are still in the development release cycle breaking changes are to be expected.

Milestone: https://github.com/PatrickSachs/helios/milestone/1

Features/Fixes

• Closes #61
• Closes #57
• Closes #56
• Closes #53
• Closes #52
• Closes #42

Breaking changes

• Your old VAPID keys will be lost, meaning all previous user subscriptions are no longer valid.