Add Helikon bootnodes.

[kukabi]

This PR adds the Helikon bootnodes to the Unique chain spec. Helikon nodes can be monitored on both the W3F Telemetry. You may test the bootnodes using the following command:

./unique-collator \
  --chain /path/to/chain/spec/unique.json \
  --relay-chain-rpc-urls=wss://rpc.helikon.io/polkadot \
  --tmp \
  --no-mdns \
  --no-telemetry \
  --no-hardware-benchmarks \
  --reserved-only \
  --reserved-nodes "/dns/boot.helikon.io/tcp/8650/p2p/12D3KooWBgfhay8zm3RhZtdDCXgfhkPmB9YEU9NjUiiztq3C13w1"

and:

./unique-collator \
  --chain /path/to/chain/spec/unique.json \
  --relay-chain-rpc-urls=wss://rpc.helikon.io/polkadot \
  --tmp \
  --no-mdns \
  --no-telemetry \
  --no-hardware-benchmarks \
  --reserved-only \
  --reserved-nodes "/dns/boot.helikon.io/tcp/8652/wss/p2p/12D3KooWBgfhay8zm3RhZtdDCXgfhkPmB9YEU9NjUiiztq3C13w1"

Thanks.

[BuddyGlas]

@kukabi
Thanks a lot for your commit, but we have long since switched to using native spec files from Parity in our networks. The relay spec files in our repository will be removed with the next release.

[kukabi]

Hi @BuddyGlas. I'm sorry for the mistake. I meant to add Unique bootnodes, not Polkadot. I created the new PR #1088 for it. Thanks!