Modernize keter

[tolysz]

Lots of changes. Mostly small additions, but also code move for ssl part.

• Builds with process 1.6
• add dependency for tls-session-manager, and it's support
• add support for ssl certs for redirects, static-files, reverse proxies
• fix http2 on reverse proxies
• make it compile with ghc-8.6.3 / lts-13.8

[tolysz]

saying:

fix http2 on reverse proxies

was a bit premature ;) i.e. there is a bit more configuration required. We use http client and server.
And there is a browser which request some HTTP version... currently it works only for some paths.

[idcm]

when build this version, there are many warning. There are only one error.
error:
• The constructor ‘FSN.Removed’ should have 3 arguments, but has been given 2
• In the pattern: FSN.Removed fp _
when I replace IGNORE by _, it compile.

[tolysz]

@idcm which version of fsnotify or resolver do you have?

[idcm]

@idcm which version of fsnotify or resolver do you have?

lts-13.13 and fsnotify 0.3.0.1
also changes
http-reverse-proxy 0.6.0
yaml 0.11.0.0
in keter.cabal

[idcm]

@tolysz
you can fix the many warning ? ;)

[tolysz]

The fixes deserve a separate commit, and a decision what is the minimum LTS.

[benjamingoldstein]

This looks really good. What is holding this back from being made into the main source code?
Alternatively, how can I get this and run it?

[mmzx]

I had been: with the addition of #203 , if you look back the history of this very PR.

[tolysz]

At this point I would need to cleanup/rebase.