For the purposes of showcasing an example, the previous `docker-compose`
was rather excessive running the Pact Broker behind a Nginx proxy with a
PostgreSQL backend. This simplifies the containers to just use the core
Pact broker image and uses `sqlite` for the database.

This commit also drops SSL/TLS from the example as it does not
meaningfully contribute to the example.

Signed-off-by: JP-Ellis <josh@jpellis.me>

Migrate the consumer example to the new example structure. This should
help reduce the redundancy between the examples and make it easier for
users to test them out and see how they work.

Ultimately, the idea will be that the consumer tests run first, and then
the provider tests run against the generated pact file.

Signed-off-by: JP-Ellis <josh@jpellis.me>

This migrates the Pact FastAPI provider from the old standalone
examples, and merges it with the new combined examples.

The consumer tests are executed first which publishes the contracts with
the broker. The provider test is then executed against the broker to
verify compliance with the published contracts.

This does, at this stage, create an unusual interdependence between
tests which typically should be avoided. I plan to fix this at a later
stage.

Signed-off-by: JP-Ellis <josh@jpellis.me>

Following the changes to the FastAPI example, this migrates the Flask
provider example to the new structure. The example relies on the
consumer having published contracts, and the flask provider is verified
against those contracts.

Signed-off-by: JP-Ellis <josh@jpellis.me>

Update the README for the examples to match the new structure of the
examples.

Signed-off-by: JP-Ellis <josh@jpellis.me>

Migrate the old isolated example and combine the test with the other
examples so that they can all be run at once.

Massive thanks to @YOU54F for identifying the switch up between the
`given` and `expected`!

Signed-off-by: JP-Ellis <josh@jpellis.me>

Try splitting the CI workflow to make use of services

Signed-off-by: JP-Ellis <josh@jpellis.me>

Initially, when having the tests completely separate, the examples were
scoped to their own space and required setting `PYTHONPATH` to work.
This is not needed if we change `import src.{mod}` to `import
examples.src.{mod}`.

Signed-off-by: JP-Ellis <josh@jpellis.me>

Signed-off-by: JP-Ellis <josh@jpellis.me>