Release 1.8.1

[jakubcech]

Description

Release 1.8.1 and test the new release pipeline.

PRs:

• Documentation: Update README cli options #1548
• Feature: Removes TipSolidifier code #1547
• Feature: Automatically request trunk and branch transactions when receiving a tx needed to solidify a milestone #1545
• Fix: Adds recently requested txs set to TransactionRequester #1543
• Fix: Read from the db in order to find the existence of spent-addresses #1540
• Fix: Up jackson-databind version to 2.9.9.1 #1534
• Fix: prevents certain HTTP API calls getting executed while the not is not synced #1533
• Fix: Rewrites request queue logic  #1530
• Change: Fixed pmd test errors #1526
• Fix: Updated discord link #1516
• Fix: Update .gitignore #1518
• Fix: Changed TX requester removal log to Debug #1515
• Update undertow and jackson #1511
• Fix: prevent self initialized connection being removed from reconnect pool too early #1506
• Fix machine6 for networking #1505
• Docker network option #1496
• Feature: Improved CW Calculation #1451
• Test: Additional unit tests to Transaction, DAGHelper and WereAddressesSpentFromProvider  #1365
• Models Documentation #1144

[GalRogozinski]

Adding observations from ICC:

1. Tangle managed to sustain up to 60 tps
2. With GTTA at depth 3 we managed to spam 12-13 tps
3. With GTTA at depth 1 we managed to spam 21 tps
4. Spam of conflicting transactions didn't raise errors and created blowballs as expected
5. Syncing failed on ICC but passed on canaries