5.0.0

• Breaking change: Library requires at least Node version 10.
• Changed: Use feature set as reported by server to determine transfer strategy.
• Changed: Test suite improvements to better reflect behaviour of an FTP server.
• Fixed: Issues around incomplete upload described in #205.
• Fixed: Variation of empty directory listing described in #206.
• Fixed: List parsing for specific Unix flavor described in #193.
• Fixed: Prevent late internal exceptions from sockets.
• Fixed: Stop explicitly destroying sockets, too early in rare cases.