Bump to 2.0.1

Update tox and travis config

Update platforms and add Pipfile

Standardize logging format

Add debug flag

Remove Pastebin from platforms

Fix Pastebin queries

Update GitHub email queries

Fix wrong results for Spotify email queries

- Add --json flag to output results as JSON

- Add support for Firefox account emails
- Python 3.6 compatibility
- Refactor various pieces of code and tests for efficiency and clarity