Update search.py

str is a keyword. Refactored variable to search_str.
Merge pull request #10 from lnunno/patch-1

Update search.py
Addeded JSON error handling
Added show_tracks example
Don't use cached tokens when scope changes
Added support for related artists
Added related artists to the README
Removed debug output
Rename scope to playlist-modify-public

Spotify's Web API has renamed the `playlist-modify` scope to `playlist-modify-public` to better describe what it allows. Even though the old one will be supported for some time, the new one is the preferred way to go.
Merge pull request #15 from JMPerez/master

Rename scope to playlist-modify-public
Added support for 'Your Music' tracks
Documentation and support for Your Music methods
Updated README and setup with version info
Add support for checking if a user's Your Music library contains a track
Add missing sys import
Fix user having to login after first token refresh

Fix issue where the get_cached_token method returns None instead of the
cached token object, meaning that users have to login again when the
initial token expires. The problem has two aspects:

- The first time the user calls get_cached_token after token
  expiration, the token is refreshed but the "new_token_info" object is
  not returned.

- The second time the user calls get_cached_token after token
  expiration, the scope check fails, because the refresh_access_token
  method didn't include the "scope" key when it cached the new
  token_info results.
Merge pull request #19 from mattduck/fix-auth-token-refreshing

Fix user having to log in after token refresh
Moved util module into main package
moved util into the main package
Updated version number