go mod update

/back, /away: Change no-op to return err
Fixes #402
When the user is not set as away, using the
`/back` or `/away` command should return error.
The previous behaviour was inconsistent,
`/away` sent a message and `/back` ignored it.
New behaviour is error for both cases.
Co-authored-by: Akshay <akshay.shekher@gmail.com>

/away: Fix output for admin whois
cc #377

host: Fix /msg vs /reply message formatting
Closes #382

sshd, chat/message: Add more debug logging for close failures

go mod update

v1.10
- `/rename`: New command for ops, rename other users and add an optional
  cosmetic prefix to their name. Github sponsors get an emoji! #352
- `/focus`: New command for ignoring everyone except the people you're
  focusing on. #356
- `/ignore`: Fixed emote messages bypassing ignores. #349
  (Thanks @medinae)
- `/names`: Sort by name! #354
  (Thanks @lucash-diskkun)
- `/whois`: Ops get to see if you're an op.
  (Thanks @pavelz)
- main: Autocomplete deprioritzes own name and sorts by last active. #355
  (Thanks @pavelz)
- `/whois`: Ops get to see the time of the user's last message.
- `/motd`: When @ is given, it will reload the motd from the file the
  server was started with. #357
- main: Fixed support for encrypted server private keys. #346
- project: Switched to Github Actions for CI, is very nice.
- project: We adopted a Code of Conduct, please review it and do your
  best to follow it: https://ssh.chat/conduct
Binaries built using go version go1.14.6.
Full list of changes here: v1.9...v1.10

v1.9
**Compatibility note for bots:** This release introduces a new bot-friendly API when `TERM=bot` is set.
- sshd/terminal: Fix full width unicode rendering bug. #339
  (Huge thanks to @yumaokao for tracking down this difficult bug.)
- sshd/terminal: Better closing of misbehaving connections.
  (Thanks @voldyman for debugging this, it was also a tricky one.)
- sshd/terminal: Add more readline-compatible navigation. #330
  (Another @voldyman contribution, thank you!)
- sshchat: Add `TERM=bot` which makes rendering more bot-friendly. #341
- sshchat: Apply `SSHCHAT_TIMESTAMP` and `SSHCHAT_THEME` env vars on connect. #333
  (Thanks @millerlogic)
- main: Added `--unsafe-passphrase`, but it's discouraged if you can use whitelisting instead. #342
- project: We got a sweet domain for the public server, `ssh.chat`!
  (Thank you @tyrelsouza for the donation.)
Binaries built using go version go1.14.
Full list of changes here: v1.8.2...v1.9

Release v1.8.2
- Fixed crash from user input. #316

Release v1.8.1
**Compatibility note for bots:** This release changes the way we format messages sent from the client, which could break some bots.
- /timestamp: Revamped to prefix each line with a timestamp, with timezone support. #297 #308
- /shrug: Ignore additional arguments
- /ban: New query-based arguments so you can ban by attribute.
- /banned: New command for ops to list banned entries.
- /op: Fixed bug where the op status was tied to the nick. #301
- /reply: Fixed bug where the reply target was not being set properly. #299
- main: `--admin` and `--whitelist` handle comments/whitespace in key files better. #298
- chat: "User left..." messages now includes time since the user joined.
- chat: Tab-complete names are now sorted by recently active.
- dev: Vendor a forked version of x/crypto/ssh/terminal with some improvements.
- dev: Various lints and code cleanups. #296
- dev: Fixed some race conditions and flaky tests. (Still more flaky tests, alas.)
- dev: Switched to go modules (from dep)
- dev: Binary releases are fully static now.
Updated for 1.8.1: Fixed crashing bug. #310
Binaries built using go version go1.12.
Full list of changes here: v1.7...v1.8.1