GitHub Action to install DotSlash

This GitHub Action installs a precompiled dotslash binary from https://github.com/facebook/dotslash/releases.

name: test suite
on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: facebook/install-dotslash@latest
      - run: ./some_dotslash_file