- Refactored Tekstowo backend to fetch lyrics directly from song pages.
- Added `encode` method to convert artist and title to their URL format,
where non-alphanumeric characters are replaced with underscores.
- Removed the now redundant search functionality and associated tests.
- Simplified `extract_lyrics` method to directly parse lyrics without
any checks.
* clean-up code & add tests for genius lyrics backend
* add genius fetch tests
* organize imports: standard lib -> pip -> local
* check in sample genius lyrics page
* fix mock import
* force utf-8 encoding for opened files
* use io.open to force utf-8 encoding w/ python2.7
