Update nixpkgs.

See merge request privatestorage/PrivateStorageio!181

Set nixpkgs explicitly in morph.

Closes #85

See merge request privatestorage/PrivateStorageio!174

Update payment metric names

See merge request privatestorage/PrivateStorageio!179

... to be in sync with https://github.com/PrivateStorageio/PaymentServer/pull/98

Add a script to update nixos version, and run it.

Closes #83

See merge request privatestorage/PrivateStorageio!165

upgrade PaymentServer

See merge request privatestorage/PrivateStorageio!178

continuously deploy develop to staging

Closes #82

See merge request privatestorage/PrivateStorageio!175

Change the on-grid continuous deployment tool to deploy the "develop" branch to the staging grid

See merge request privatestorage/PrivateStorageio!176

Avoid copying nixpkgs to the store a second time in nix-shell.

See merge request privatestorage/PrivateStorageio!168

Quotes required for correct operation if there are spaces or some other
shell-special characters

Allow building the local grid with a clean checkout.

Closes #86

See merge request privatestorage/PrivateStorageio!171

Move NixOS systems tests to `nixos/tests`.

See merge request privatestorage/PrivateStorageio!173

Don't include vagrant in shell.nix if running in a container.

See merge request privatestorage/PrivateStorageio!167

Don't wait for cerbot before starting PaymentServer.

See merge request privatestorage/PrivateStorageio!170

Remove some out of date references.

See merge request !169

Since !146, PaymentServer is proxied behind nginx, so there is no need to wait
for certificates or network interfaces before starting the server.

Expose all local packages as new module argument.

Closes #81

See merge request privatestorage/PrivateStorageio!163