GitHub Actions workflow on push

[battila7]

Brief

As a bigger goal, we want a nice Continuous Delivery pipeline for cryptid-js. However, even the greatest journey starts with a single step, so for a starter, let's implement a Continuous Integration workflow.

Task

Create a new GitHub Actions workflow that

• runs on
  • push to master
  • PR to master
• executes the lint script and fails if the codebase is not properly linted/formatted.

Dependencies

Depends on #7