Extension: pass-mount 0.1.0 released

[William Morris]

Hello everyone,

Initial `udisks` support has been added to
[pass-mount](https://github.com/HXR/pass-mount) version 0.1.0

This extension allows `pass` to unlock encrypted volumes in user-space,
which should provide for better desktop integration on Ubuntu 18.04 and
anything else running udisks.

Given a USB drive with a LUKS partition that has a UUID of
`222254e3-c547-4b4e-823a-5181698e0a39`, a disk label of `data`
and a multi-line entry `usb` in pass
```
encrypted-volume-password-here
type: udisks
uuid: 222254e3-c547-4b4e-823a-5181698e0a39
```
the command `pass mount usb` will then mount the encrypted partition to
`/media/$USER/data` or wherever udisks normally mounts user volumes.

Feedback and pull requests are welcome!