Consider randomizing mnemonic used to initialize balances

[serejke]

axon-cli/src/assets/config_template.toml

Line 14 in 0faef69

mnemonic = "test test test test test test test test test test test junk"

is hardcoded and makes it to the final node_1.toml / node_2.toml, etc, meaning that the default 10 wallets will be initialized with 100..000 Axon ETHs. This mnemonic is publicly known so anyone can drain all funds from these wallets.

Consider generating a random mnemonic as part of axon config-gen script.