feat: automatically enable allowHTTP1 by default with http2 & hmr

[illusionalsagacity]

This PR contains:

• bugfix
• feature
• refactor
• tests
• documentation
• metadata

Breaking Changes?

• yes
• no

If yes, please describe the breakage.

Changes the default configuration for the http2 server if hmr is true.

Please Describe Your Changes

relates to #183 and #184

I added the tls-keygen dev dependency in order to generate the keys, unfortunately browsers do not seem to support unencrypted http2 at this time, even on localhost. Probably worth some followup work to make the http2 option require some of the http2.createSecureServer options to avoid any footguns?

[shellscape]

I see the new test fixtures added, but not any tests. Is that pending or uncommitted?

[shellscape]

Suggested change

	_Note: If using in combination with `http2`, the `http2` option `allowHTTP1` will enabled by default for the HMR WS connection to work._
	_Note: If using in combination with `http2`, the `http2` option `allowHTTP1` will be enabled by default for the HMR WS connection to work._

[illusionalsagacity]

Yeah, pending I will add another case for it.

[illusionalsagacity]

So I can't get the integration tests to run to completion locally, particularly the multi-hmr one seems to be troublesome. It does happen as well on the master branch, so I'm not quite sure what is going on there.

[bebraw]

Can you tell more about the test issue? How does it fail exactly?

[shellscape]

@illusionalsagacity I'll try and step into your branch to get the tests work. probably later this week.

[illusionalsagacity]

@illusionalsagacity I'll try and step into your branch to get the tests work. probably later this week.

Alright, thanks. To answer @bebraw the issue I'm seeing is that chromium just sits on the about:blank page and the tests hang for me. Probably related to some of the changes I made with the puppeteer config, I would assume.