Fix instructions for building Caddy from source

* run go mod tidy

* import the right version of quic-go

Fix #2560

* Add link to Good First Issue

 in Contributing Section

* Fix heading

Temporary until Go 1.13

* Migrate to gomods

* Fix conflict

* gomod: Switch xenolf/lego to go-acme/lego

* Set up CI with Azure Pipelines [skip ci]

* Add other platforms [skip ci]

* Oops, add vmImage back in [skip ci]

* Fix goVersion [skip ci]

* Use sudo to install Go [skip ci]

* Attempt platform-specific Go isntalls [skip ci]

* Try sharing the variable a different way [skip ci]

* Trying this again... [skip ci]

* Fix the PATH [skip ci]

* Fix GOROOT, hopefully [skip ci]

* More fixing [skip ci]

* Still fixing [skip ci]

* Add golang-ci [skip ci]

* asdfasdfasf [skip ci]

* Sigh, work around broken golangci-lint installer [skip ci]

* Try again [skip ci]

* ahhhhhh [skip ci]

* sooooo close! cleanup [skip ci]

* oh c'mon [skip ci]

* thought I had it for a sec [skip ci]

* yaaaayyyy [skip ci]

ship it

* caddy: Rename env flag to envfile

* caddy: Add env flag to print environment variables

* Add upstream header replacements (TODO: tests, docs)

* Add tests, fix a few bugs

* Add more tests and comments

* Refactor header_upstream to use a fallthrough; return regex errors

as per https://help.github.com/en/articles/creating-a-pull-request-template-for-your-repository

* Move SiteOutput to a seperate function sorted by port.

* Rename vars and tidy up

* Move loopback note to output loop

* Fix Typo

* Remove unneeded var

* Readability Change

* Change to other port string.

* Simplify as all sites in Server use the same port

* Ensure -quiet supresses fmt.Println calls

* Prevent double output of siteinfo to log - improve log message

* change name of log in comment

* Remove spaces

* Remove extra line output

* final tidy!

* Use caddy.LogDestination to setup log

* Ensure Log is still output if quiet.

* Correct case of functions and make function param bool

* Remove conditional check for LogDestination

* Revert output to simple blocks

* comment update

* Can simply add user to replacer before Replace call.  user is then also added to logs

* use fmt.Errorf

* fix how fmt.Errorf is called.

* Check errors directive only has 1 argument

* Added Tests

removed "names": is not used

This reverts commit c0190a34.

* Move SiteOutput to a seperate function.

* Simplify as all sites in Server use the same port

* Ensure -quiet supresses fmt.Println calls

* Prevent double output of siteinfo to log - improve log message

* Use caddy.LogDestination to setup log

* Ensure Log is still output if quiet.

* Append Internal paths to Caddy config HiddenFiles

* gofmt

* Reuse a variable

* Update caddyhttp/internalsrv/setup.go
Co-Authored-By: magikstm <myskina@gmail.com>

* proxy.AllowedPath: Re-append trailing slashes to excepted path comparisons

* Substitute HasSuffix for manual check; check slash was actually removed

* log basicauth errors

* Fixed tests

* Fix log include

* Remove some unneeded blank lines.