v0.3.0

0x prefixes:

• Allow both 0x and non 0x prefixed ETH1 public key in --fee-recipient flag
• Allow both 0x and non 0x prefixed validators public key in file corresponding to --pubkeys-file-path flag

Fix --fee-recipient bug:

• When using --fee-recipient flag with external block building, the actual fee recipient is not the one specified in the --fee-recipient flag, and the corresponding execution block contains at least one transaction with no to (example: smart contract deployment), then the watcher crashes. This release fixes this bug.