Repository: youtube-dl
Issue: Site support request: Spotify
Labels: site-support-request,account-needed

### Make sure you are using the _latest_ version: run `youtube-dl --version` and ensure your version is _2016.08.13_. If it's not read [this FAQ entry](https://github.com/rg3/youtube-dl/blob/master/README.md#how-do-i-update-youtube-dl) and update. Issues with outdated version will be rejected.
- [x] I've **verified** and **I assure** that I'm running youtube-dl **2016.08.13**
### Before submitting an _issue_ make sure you have:
- [x] At least skimmed through [README](https://github.com/rg3/youtube-dl/blob/master/README.md) and **most notably** [FAQ](https://github.com/rg3/youtube-dl#faq) and [BUGS](https://github.com/rg3/youtube-dl#bugs) sections
- [x] [Searched](https://github.com/rg3/youtube-dl/search?type=Issues) the bugtracker for similar issues including closed ones
### What is the purpose of your _issue_?
- [ ] Bug report (encountered problems with youtube-dl)
- [x] Site support request (request for adding support for a new site)
- [ ] Feature request (request for a new functionality)
- [ ] Question
- [ ] Other
### If the purpose of this _issue_ is a _bug report_, _site support request_ or you are not completely sure provide the full verbose output as follows:

Add `-v` flag to **your command line** you run youtube-dl with, copy the **whole** output and insert it here. It should look similar to one below (replace it with **your** log inserted between triple ```):

```
$ python -m youtube_dl https://play.spotify.com/user/starsam80/playlist/3Cwl7TvjAgsVvs1KF7jxbs --verbose
[debug] System config: []
[debug] User config: []
[debug] Command-line args: ['https://play.spotify.com/user/starsam80/playlist/3Cwl7TvjAgsVvs1KF7jxbs', '--verbose']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2016.08.13
[debug] Git HEAD: aaf44a2
[debug] Python version 3.5.2 - Linux-4.7.0-1-ARCH-x86_64-with-arch-Arch-Linux
[debug] exe versions: ffmpeg 3.1.2, ffprobe 3.1.2, rtmpdump 2.4
[debug] Proxy map: {}
[generic] 3Cwl7TvjAgsVvs1KF7jxbs: Requesting header
WARNING: Falling back on generic information extractor.
[generic] 3Cwl7TvjAgsVvs1KF7jxbs: Downloading webpage
[generic] 3Cwl7TvjAgsVvs1KF7jxbs: Extracting information
ERROR: Unsupported URL: https://play.spotify.com/user/starsam80/playlist/3Cwl7TvjAgsVvs1KF7jxbs
Traceback (most recent call last):
  File "/home/starsam80/.local/lib/python3.5/site-packages/youtube_dl/YoutubeDL.py", line 691, in extract_info
    ie_result = ie.extract(url)
  File "/home/starsam80/.local/lib/python3.5/site-packages/youtube_dl/extractor/common.py", line 347, in extract
    return self._real_extract(url)
  File "/home/starsam80/.local/lib/python3.5/site-packages/youtube_dl/extractor/generic.py", line 2344, in _real_extract
    raise UnsupportedError(url)
youtube_dl.utils.UnsupportedError: Unsupported URL: https://play.spotify.com/user/starsam80/playlist/3Cwl7TvjAgsVvs1KF7jxbs
```

---
### If the purpose of this _issue_ is a _site support request_ please provide all kinds of example URLs support for which should be included (replace following example URLs by **yours**):
- Single song: https://play.spotify.com/track/7zsXy7vlHdItvUSH8EwQss
- Playlist (Top 50): https://play.spotify.com/chart/6o9o1UphRtyv10VPuDT80D
- Playlist (User created): https://play.spotify.com/user/starsam80/playlist/5VFlb4iQz3RADlqHrp5kQe
- Playlist (An artist): https://play.spotify.com/artist/3sS2Q1UZuUXL7TZSbQumDI

---
### Description of your _issue_, suggested solution and other information

Since there is support for Soundcloud, I don't see why Spotify can't be supported. The links above _may_ be blocked by a simple login, but you can create a free account if needed. https://developer.spotify.com/ also looks useful.