Spring cleaning

[emgrav]

We have a few outstanding issues to fix (#162, #160). As part of this we will need to bump dependencies and do some overall spring cleaning. Most important dependency bumps are firebae-cm and gcp_auth, but we should take the opportunity to bump everything.

We also made the decision to use firebae-cm ~3 years ago. There may be better options than this crate these days, this should also be looked into.

Steps to implement

• Update gcp_auth
• Update (or replace if applicable) firebae-cm
• General dependency bump
• Resolve Add configuration option for apns-push-type #160 and Connecting to Firebase fails with invalid URL, scheme is not http #162