upgrade dependency

[mohitpubnub]

• upgrade proxy-agent dependency

[mohitpubnub]

@TooTallNate can we have this dependency upgraded

[robbkidd]

@mohitpubnub I am not a maintainer on this project, but I predict that they will not want the new files I commented on below included in the proxy-agent dependency bump.

[robbkidd]

This PR is related to #48.

[mohitpubnub]

May be it's a bit clean now!

[robbkidd]

It's clean-er now, certainly. Thanks!

As you can see from #48, getting a release out may be more complicated than just this dependency bump.

[dargmuesli]

What would make it more complicated than an merge of this PR and a release, @robbkidd?

[robbkidd]

@dargmuesli The changes in this PR are insufficient to keep superagent-proxy working with proxy-agent v6, a major version bump. This simple upgrade causes superagent-proxy to fail wiring up a proxy configuration onto superagent clients.

I have attempted to demonstrate that failure in #50, which is a duplicate of this PR's dependency bump that I applied after I fixed the tests and added a CI workflow. The new workflow is not accepted as I write this, so in the meantime you can see the failures in a demonstration on my fork. #50 now has running CI tests and shows to problem and progress toward addressing it.

Hopefully I've added enough test infrastructure for people more knowledgeable than I am about ES modules to work an update for the import.

[TooTallNate]

You're gonna have to do const { ProxyAgent } = require('proxy-agent'). There is no longer a default export.