## Issue Addressed
Resolves#2094
## Proposed Changes
Fixes scripts for creating local testnets. Adds an option in `lighthouse boot_node` to run with a previously generated enr.
## Proposed Changes
A couple of minor fixes to the testnet scripts.
First, `clean.sh` only attempts to remove the directory if it exists. This ensures a good exit code even if the directory is not present.
Second, `setup.sh` uses an updated deposit contract address to match that in the generated spec to allow the chain to start.
## Issue Addressed
#1494
## Proposed Changes
- Give the TaskExecutor the sender side of a channel that a task can clone to request shutting down
- The receiver side of this channel is in environment and now we block until ctrl+c or an internal shutdown signal is received
- The swarm now informs when it has reached 0 listeners
- The network receives this message and requests the shutdown
