Cleanup Cassandra dockerfile
Remove server_endpoint from preprod template

We either want this to actually be set to 127.0.0.1 or we want to update
it at runtime.
Add PYTHONPATH
Remove java and cassandra builds from runner

We don't need to build these on every run
Fix OTTER_ENVS
Move cloudcafe into it's own run script

This allows us to update the IP at runtime meaning we can use one
container for both otter and cloudcafe, simplifying things and stuff