Add SecureDrop

[brainwane]

Per https://securedrop.org/news/securedrop-100-released/ :

Python update: This release transitions the SecureDrop application code and all its dependencies to run under Python 3. This is part of a full transition of SecureDrop to Python 3 before the end-of-life date for Python 2 (January 1, 2020).

freedomofpress/securedrop#4355
freedomofpress/securedrop#4622

[takluyver]

Thanks! If anyone's looking to do this, please ask the securedrop maintainers to discuss it - we always get project maintainers agreement before adding their name to the statement, even if they've dropped Python 3 support.

[takluyver]

I'm closing all 'add $PROJECT' issues now - the statement has served its purpose and we're archiving it. Thanks!