Pueblo

- Testing: Add `pueblo.testing.notebook.{list_path,generate_tests}`

- ngr: Add capability to invoke Python's built-in `unittest`

- Testing: Add `pueblo.testing.pandas.{makeTimeDataFrame,makeMixedDataFrame}`.
They have been removed from `pandas._testing` on behalf of pandas 2.2.0.

- Packaging: Fix `MANIFEST.in`

- Dependencies: Update to pytest-notebook >=0.10,
lower versions are not compatible any longer
- ngr: Add capability to invoke Meltano projects

- Add a few testing helper utilities to `pueblo.testing`
- Fix dependencies for `test` extra by downgrading to `nbdime<4`
- Dependencies (extras): Remove "ngr", add "notebook", link "test" to "testing"
- ngr: Gradle test runner failed to invoke `./gradlew install` because such a
target did not exist.
- ngr: Fix Gradle test runner by only conditionally invoking `gradle wrapper`
- ngr: Add capability to invoke projects using the `poethepoet` task runner
- Dependencies: Update to nbdime 4 and pytest-notebook 0.10
- Add `pueblo.io.to_io` utility function
- ngr: Improve .NET runner by accepting `--dotnet-version` command-line option
- ngr: Fix Gradle test runner by wiping existing Gradle wrappers, to accommodate
for contemporary versions of Java
- Add support for Python 3.7
- Add `testbook` to `notebook` subsystem
- Add `pueblo.util.proc.process` utility. It is a wrapper around
`subprocess.Popen` to also terminate child processes after exiting.
Thanks, pcattori.