Use Node.js 14 tsconfig configuration

[n1ru4l]

See https://github.com/nodejs/release#release-schedule

The minimum version supported in maintenance mode is Node.js 14, thus it is legit to increase the target ECMA version.

e.g. to https://github.com/tsconfig/bases/blob/main/bases/node14.json

LTS graphic: https://github.com/nodejs/release#release-schedule

Current version:

supertokens-node/lib/tsconfig.json

Line 3 in 76a983f

"target": "ES2016",

This change will result in less verbose transforms (such as async await to generators etc.)