Fix local testnet scripts (#2229)

## 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.

scripts/local_testnet/beacon_node.sh

@@ -2,20 +2,22 @@
 
 #
 # Starts a beacon node based upon a genesis state created by
-# `./local_testnet_genesis_state`.
+# `./setup.sh`.
 #
+# Usage: ./beacon_node.sh <DATADIR> <NETWORK-PORT> <HTTP-PORT> <OPTIONAL-DEBUG-LEVEL>
 
 source ./vars.env
 
-DEBUG_LEVEL=${1:-info}
+DEBUG_LEVEL=${4:-info}
 
 exec lighthouse \
 	--debug-level $DEBUG_LEVEL \
 	bn \
-	--datadir $BEACON_DIR \
+	--datadir $1 \
 	--testnet-dir $TESTNET_DIR \
-	--dummy-eth1 \
-	--http \
+	--staking \
 	--enr-address 127.0.0.1 \
-	--enr-udp-port 9000 \
-	--enr-tcp-port 9000 \
+	--enr-udp-port $2 \
+	--enr-tcp-port $2 \
+	--port $2 \
+	--http-port $3