Helper functions for pinnwand providers and more!

Provider news in 3.2.1 from 3.2.0:

• Add bpa.st as a provider.
• Add paste.rs as a provider.

New features in 3.2.1 from 3.2.0:

• bpa.st is using a software known as pinnwand which is an open
  source pastebin software: https://github.com/supakeen/pinnwand

  So now we have generic helper function to easily add other pinnwand
  providers in the future.

Project news in 3.2.1 from 3.2.0:

• We had 9 commits by 2 different authors.
• Drop travis-ci.org in favor of github actions.