Implement diffing logic

This is a small release extending the container matching logic with a diff, which gets displayed in the logs. This helps tracing the runner behaviour and figuring out why containers are shutdown or reused across different runs.

Implement container networking

• Run containers in a custom bridge network, with name derived from the values the user sets in AppTag
• Allow to directly address containers by name
• introduce algebra.PortSpec, for a better control of the port binding behaviour. User can now chose between an explicit host-container port mapping, or just let the library pick an available host port from a given range
• Remove support for Future

introduce `ServicesByRef`

Introduce a wrapper type to simplify access to running containers' locations (i.e. port/host). This involves a breaking change to the API, as the Runner#setUp method now returns a ServicesByRef object and not a non-empty list of Service.Registered.

v0.1.5

This is a bugfix release solving a major issue in the implementation of Scheduler[IO], which was previously not honouring the supplied attempt/overall timeouts.