proxy: refactor TestUpstreamHeadersUpdate and TestDownstreamHeadersUpdate

Signed-off-by: Tw <tw19881113@gmail.com>

basicauth: Remove Authorization header on successful authz (issue #1324)

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If a site owner protects a path with basicauth, no need
to use the Authorization header elsewhere upstream, especially since it
contains credentials.

If this breaks anyone, it means they're double-dipping. It's usually
good practice to clear out credentials as soon as they're not needed
anymore. (Note that we only clear credentials after they're used,
they stay for any other reason.)

* Fix #2 (Replacement doesn't happen - https://github.com/echocat/caddy-filter/issues/2) bug of caddy-filter

* Fixed gofmt issue.

* Remove comment of reason why we do a reorder

* Added path cleanup functions with masking to preserve certain patterns + unit tests, #1298

* Use custom PathClean function instead of path.Clean to apply masks to preserve protocol separator in the path

* Indentation corrected in the test data map to pass the lint

* Fixing ineffassign of a temporary string variable

* Improved variable naming and documentation

* Improved variable naming

* Added benchmarks and improved variable naming in tests

* Removed unnecessary value capture when iterating over a map for keys

* A typo correction

Fixed #1292 and resulting issues from #1300

* Remove pre 0.9 code

* Unused import

* gofmtw

This issue was caused by connHijackerTransport trying to record HTTP
response headers by "hijacking" the Read() method of the plain net.Conn.
This does not simply work over TLS though since this will record the TLS
handshake and encrypted data instead of the actual content.
This commit fixes the problem by providing an alternative transport.DialTLS
which correctly hijacks the overlying tls.Conn instead.

* Fixed HTTP/2 support for the proxy middleware

http.Transport instances whose TLSClientConfig, Dial, or DialTLS field
is non-nil will be configured without HTTP/2 support by default.

This commit adds the proper calls to http2.ConfigureTransport()
everywhere a http.Transport is created and thus fixes HTTP/2 in the
proxy middleware whenever insecure_skip_verify or keepalive is provided.

* Added HTTP/2 support check to TestReverseProxyInsecureSkipVerify

* Feature #1282 - Support pre-gzipped files

* Fix broken test cases

* Support brotli encoding as well

* Fix for #1276 - support integers and floats as metadata in markdown (#1278)

* Fix for #1276

* Use strconv.Format

* Use map[string]interface{} as variables

* One more file

* Always run all tests before commit

* Get rid of DocFlags

* Fix syntax in caddy.conf

* Update to Go 1.7.4

* Add send_timeout property to fastcgi directive.

* Convert rwc field on FCGIClient from type io.ReadWriteCloser to net.Conn.
* Return HTTP 504 to the client when a timeout occurs.
* In Handler.ServeHTTP(), close the connection before returning an HTTP
502/504.
* Refactor tests and add coverage.

* Return HTTP 504 when FastCGI connect times out.

* test: add unit test for #1283 (#1288)

* After review fixes

* Limit the number of restarts with systemd

* Prevent fd leak

* Prevent fd leak

* Refactor loops

* gofmt

* Fix for issue #1287 - hide hidden files

* Reuse IsHidden

* Fix failing tests

Add send_timeout property to fastcgi directive

Update to Go 1.7.4

Fix syntax in caddy.conf

* Convert rwc field on FCGIClient from type io.ReadWriteCloser to net.Conn.
* Return HTTP 504 to the client when a timeout occurs.
* In Handler.ServeHTTP(), close the connection before returning an HTTP
502/504.
* Refactor tests and add coverage.

* Fix for #1276

* Use strconv.Format

* Use map[string]interface{} as variables

* One more file

* Always run all tests before commit

* Get rid of DocFlags

* Fix for #1164 - allow only one header per line

* Include original reporter case