Include "getTokens" using faucet command.

[fboucquez]

Currently, when a user creates a testnet node, it needs to go to the faucet and send some tokens to the node signing account in order to complete the link keys registration. This step could be improved by adding a command that sends tokens to the account using faucet (of course this is only available for test networks with facuet).

The faucet rest method is:

POST http://faucet-0.10.0.x-01.symboldev.network/claims
JSON Body
{
    "amount": 0,
    "recipient": "TCFV4TKV6RMN7QPR3PTBXDWIJCLXDVKSIPEEUAQ",
    "selectedMosaics": ["5B66E76BECAD0860"]
}

Examples:

symbol-bootstrap getTokens 
symbol-bootstrap getTokens  --address "someAddress"

By default, the address is the signing address if preset ("just API" nodes don't have signing keys).

There will be a validation to avoid overuse. if the account has more than X amount of tokens, the command will log and ignore