Release 1.6.0

¡We are ready to join low diff pools!

Miner mandatori update.
All miners should uptade to this version to be compatible with low diff pools:

• Solved bugs found on merkle root calculations. (@golden-guy)
• Solved issues about difficulty calculation (@golden-guy)
• Tested on low difficulty pools. (NerdMinerTeam)
• Changed the default pool to http://public-pool.airdns.org/
• Added new notes to readme about supported pools (@BitMaker-hub)
• Added new custom sha tests to use on next versions (@BitMaker-hub)

You can also build it easily using the flasher tool:
https://bitmaker-hub.github.io/diyflasher/