drop old nodejs support

[L2jLiga]

Currently chai-http supports node >= 4 and node < 10 already EoL.

Are there any reasons to support such versions of node?

[keithamus]

Hey @L2jLiga thanks for the issue.

We tend to drop support for older EOL versions of Node once we have a reason to make a breaking major release. At current, we have no plans to make a major release - but there is an effort to drop SuperAgent (#203) which will require such a release - at which point we'll drop support for any EOL Node versions.

I'll close this, as there's nothing actionable in of this issue. We'll drop older versions when we cut a major release.