IoTeX Dev Update Week 12/09/2019

[Yutong]

• added option to start libp2p private network(#1732)
• more testing(#1736 #1755)
• refactor works are still on going(#1739 #1724 #1749 #1761 #1763 #1743 #1764 #1783 #1784 #1751)
• bug fixings (#1760 #1780)

[Artanovskaya]

Dev team does not sleep😉 great, guys👍🏻