Overwrite `cassandra-embedded.yaml` file when starting the server to avoid an error is the file already exists (#5725)
Overwrite `cassandra-embedded.yaml` file when starting the server to avoid an error is the file already exists (#5725)

## What is the goal of this PR?

When running tests it has been possible for the GarknTestServer to end up in an unclean state and to fail to start. We believe this is from failing to supply `spawn_strategy=local` when running tests.

## What are the changes implemented in this PR?

- Overwrite `cassandra-embedded.yaml` file when starting the server to avoid an error if this file already exists

graknlabs/grakn,graknlabs/grakn,lolski/grakn,graknlabs/grakn,lolski/grakn,graknlabs/grakn,lolski/grakn,lolski/grakn