Summary of changes

• Expose git_remote_rename
• Bump OpenSSL from 1.1.0i -> 1.1.1c in Windows/Mac OS Electron builds
• Replace unmaintained request library with got
• Remove promisify-node and use vanilla promises for all NodeGit promises
• Prebuilds for Node 14, deprecate Node 8
• Persist RemoteCallbacks and ProxyOptions on the remote if using Remote.prototype.connect. This fixes a segfault when using any routines on a connected remote.

Merged PRs into NodeGit

• Upgrade build environments #1785
• Remote needs to persist the callback/proxyOpts/headers #1784
• Remove promisify-node and remove old callback api remnants
• Replace deprecated package request with got
• Bump OpenSSL prebuilt to 1.1.1c
• Expose git_remote_rename
• Dedupe Remote.prototype.fetch