New mail notifications appear not to be working

[Protuhj]

Opening the app when I know I have new mail to read, the envelope doesn't show in my notification area.

[Jolt151]

See #79

[Protuhj]

Do we need to add this new way of doing notifications then?

How much are you caring about backwards compatibility?

[zagaberoo]

Google Play at least is going to keep forcing the target API up over time it seems. Given how few downloads my direct links get for each release, focusing on Play makes sense. So, we should try and stay compatible where possible, but people can always stick with older versions if we need to bump things up for important functionality like mail.

[Jolt151]

Fixed by #92