Changed schema (#7)

Changed SQLite schema to implement echonest.
Echonest wrapper (#7)

Implemented echonest wrapper.
Started adapting new schema (#7)

Started to adapt new SQLite schema.
Added virtualenv and Heroku Procfile
Moved venv in gitignore
Resolved merging conflicts
Added pyechonest to libs
Changed requirements.txt
Added an Echonest wrapper (#7)

Added a class that conveniently wraps the Echonest API.
Changed schema (#7, #9)

Added a songs table and moved several columns for database
normalisation.
Adapted some column types to PostgreSQL (SERIAL, TIMESTAMP).
Integrated the Echonest wrapper (#7)

Integrated the Echonest wrapper in existing code.
Added models, refactored code

Added new models that reflect the new schema and also refactored code.
Added a Soundcloud wrapper

Added a class that conveniently wraps the Soundcloud API.
Merge pull request #18 from linkyndy/echonest-integration

Echonest integration