Accept dir and file after /-/

Closes #16

See merge request !169

v0.2.1

See merge request !167

Ignore NoErrAlreadyUpToDate error when cloning a steps repo

See merge request !166

Initial working dir CI_PROJECT_DIR in CI

Closes #129

See merge request !165

The documentation for git.Repository.FetchContext states:

    Returns nil if the operation is successful, NoErrAlreadyUpToDate if there are no changes to be fetched, or an error.

We need to ignore that "non"-error.

Upgrade tests to use the latest step runner

See merge request !164

Remove support for steps: syntax in JSON schema

See merge request !145

Increase end-to-end test coverage

See merge request !151

Add and test steps tutorial examples

See merge request !163

Make the initial `Run` API call wait for the connection to be ready

See merge request !161

Over in the runner repo, the steps-integration integration tests are
failing withe following error:

        ERROR: Job failed (system failure): container exec on "fb713040a3f77c360ea1c8a7829c03c6a9f91cf3189952b03c9ae347df352e78" finished with: executing step request: running job request: rpc error: code = Unavailable desc = connection error: desc = "error reading server preface: io: read/write on closed pipe"

The error appears to be caused by sending the Run request before the
connection is actually ready. This CallOption waits for the connection
to be ready before sending the Run request.

See:
* https://grpc.io/docs/guides/wait-for-ready/
* https://pkg.go.dev/google.golang.org/grpc#WaitForReady

Note! To avoid a circular dependency I've had to move this to a separate package. However, because many of the tests
reference the unexported `jobs` field, I used the export_test trick to make it accessible TO TEST IN THIS PACKAGE ONLY.

This type just wraps the existing StepRunnerService and adds some test
specific bits to it, like getting client connection and properly
shutting down.

Next I'll rework many of the existing tests to use this instead of the
in-memory listener.

I'll need use the code to get TCP listener at a free TCP port in another
test type, so I'll refactor this a bit and export it.

The error trace in the relevant failed runner integration tests was
actually sufficient to pinpoint the source of the failure, but ti could
still be improved a bit.

Update the step file format to use a file with JSON on each line

See merge request !159

Log name of executable step

See merge request !158

The export_file format is the same as the output_file format

See merge request !157

Inline gitReference for simplicity and clarity

See merge request !152

Merge union the changelog file

See merge request !153

Remove obsolete service test

See merge request !155

Over in 31804b18 we removed explicit handling of context cancellation
before job execution start. The test removed here was testing that case
specifically. This test and the one immediately below it now effectively
test the same scenario/code path, so this one is redundant.