Add support for albums - Githubissues

Passing an URL for album causes script to crash as mentioned in #50


D:\Google Drive Folder\MyMusic_G_Drive>spotify-dl https://open.spotify.com/album
/5YBY91ePHZWzgsLRrDK8DI
warning:expected id of type album but found type https spotify:album:https://ope
n.spotify.com/album/5YBY91ePHZWzgsLRrDK8DI
Traceback (most recent call last):
  File "c:\program files (x86)\python35-32\lib\site-packages\spotipy\client.py",
 line 107, in _internal_call
    r.raise_for_status()
  File "c:\program files (x86)\python35-32\lib\site-packages\requests\models.py"
, line 937, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 404 Client Error: Not Found for url: https://api.
spotify.com/v1/albums///open.spotify.com/album/5YBY91ePHZWzgsLRrDK8DI

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\program files (x86)\python35-32\lib\runpy.py", line 184, in _run_modu
le_as_main
    "__main__", mod_spec)
  File "c:\program files (x86)\python35-32\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Program Files (x86)\Python35-32\Scripts\spotify-dl.exe\__main__.py",
line 9, in <module>
  File "c:\program files (x86)\python35-32\lib\site-packages\app\app.py", line 4
4, in main
    album = sp.album(urn)
  File "c:\program files (x86)\python35-32\lib\site-packages\spotipy\client.py",
 line 289, in album
    return self._get('albums/' + trid)
  File "c:\program files (x86)\python35-32\lib\site-packages\spotipy\client.py",
 line 133, in _get
    return self._internal_call('GET', url, payload, kwargs)
  File "c:\program files (x86)\python35-32\lib\site-packages\spotipy\client.py",
 line 114, in _internal_call
    -1, '%s:\n %s' % (r.url, 'error'))
spotipy.client.SpotifyException: http status: 404, code:-1 - https://api.spotify
.com/v1/albums///open.spotify.com/album/5YBY91ePHZWzgsLRrDK8DI:
 error```
SathyaBhat / spotify-dl

Add support for albums #52
