Migrate to eslint, plus changes to make eslint stop bitching

[trasherdk]

Enable package-lock.json

• Add deprecated list (to-do stuff)

eslint: Install latest version 7.27.0

• generate a basic config

format: reduce indent to 2 spaces

.gitignore: Adding dotenv

• prepare for test on real server

Remove obsolete use strict

editorconfig: reduce indent to 2 space

lib/imapSimple.js: var to const or let

• indent 2 spaces
• unnamed function to arrow
• change increment ++ to += 1
• concat string to template string
• new Buffer() to Buffer.from()

eslint: Stop whining like a bitch

testserver: wrap listen in a try/catch to reject on error

test: move require to top

• add catch to startserver

deps: add dotenv

deps: bump non-dev dependencies "iconv-lite": "^0.6.3", "imap": "^0.8.19", "nodeify": "^1.0.1", "quoted-printable": "^1.0.1", "utf8": "^3.0.0", "uuencode": "0.0.4"