I could neither run the upstream Docker image nor could I build the Dockerfile.
Bug 1
-----
Cannot run the upstream image:
```
docker pull jess/spotify
docker run -it --rm jess/spotify
spotify: error while loading shared libraries: libSM.so.6: cannot open shared object file: No such file or directory
```
Solution to bug 1
-----------------
Install `libsm6`
Bug 2
-----
Cannot build the Dockerfile:
```
cd dockerfiles/spotify
docker build . --pull
[...]
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
Executing: /tmp/apt-key-gpghome.k3eQma7IzG/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-keys 4773BD5E130D1D45
gpg: key 4773BD5E130D1D45: public key "Spotify Public Repository Signing Key <tux@spotify.com>" imported
gpg: Total number processed: 1
gpg: imported: 1
Hit:1 http://deb.debian.org/debian sid InRelease
Get:2 http://repository.spotify.com stable InRelease [3316 B]
Err:2 http://repository.spotify.com stable InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D1742AD60D811D58
Reading package lists...
W: GPG error: http://repository.spotify.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D1742AD60D811D58
E: The repository 'http://repository.spotify.com stable InRelease' is not signed.
The command '/bin/sh -c apt-get update && apt-get install -y dirmngr gnupg --no-install-recommends apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 4773BD5E130D1D45 echo "deb http://repository.spotify.com stable non-free" >> /etc/apt/sources.list.d/spotify.list && apt-get update && apt-get install -y sa-utils libgl1-mesa-dri libgl1-mesa-glx libpulse0 spotify-client utils --no-install-recommends && rm -rf /var/lib/apt/lists/*' returned a non-zero code: 100
```
Solution to bug 2
-----------------
Replaced instructions to retrieve the key with the official instructions from https://www.spotify.com/us/download/linux/
