Run CI outside of container

[DaniBodor]

Once #302 is complete, we should rewrite build.yml such that it does not need a container to be installed. This will make the file easier to read and maintain in the future, and makes the process more transparent.

[DaniBodor]

When rewriting, also fix #301

[psomhorst]

The tests are currently running outside a container, but get data from a closed source container.

Closed in favor of #383.