Package was originally created with use of [python-pypi2pkgbuild](https://aur.archlinux.org/packages/python-pypi2pkgbuild)
```
pypi2pkgbuild.py -I dagger-io
```
But it seems to be abandoned for quite some time. So I rewrote the `PKGBUILD` file, and while at it enabled `check()` function with tests.