Set up integration testing and GitHub actions #10
Description
Issue 1
The repository contains unit tests but lacks an integration test that verifies the CLI can build the PETPrep workflow on a minimal BIDS dataset. This limits confidence that the command-line interface functions correctly end‑to‑end.
Issue 2
Only one GitHub workflow exists (coverage.yml). There is no CI job that runs the test suite (including the new integration test) on push or pull request.
Issue 3
Documentation does not mention running the integration tests or the new GitHub workflow, so contributors may be unaware of them.