Fix compression of *os.Files. (gorilla#197)

After using httpsnoop to preserve interfaces, the compress response
writer now implemented ReaderFrom. ReaderFrom is used by net/http to
use sendfile when serving *os.Files. This breaks compression because
it serves directly to the underlying response writer, skipping the
compressor. Fix by implementing ReadFrom on our resposne writer to
copy to our compressor.

Fixes gorilla#194.

Support logger for print stack trace (gorilla#195)

Fixes gorilla#171

docs: fix missing CircleCI badge (gorilla#166)

Create release-drafter.yml (gorilla#163)

added ability to register custom log formatter (gorilla#131)

* added ability to register custom log formatter

* changed function type declaration to work on older versions of Go

* changed to an args struct per PR, refactored logging tests to make it easier to see the scenarios

* fixed formatting and linting issues

* split logging into its own file

* removed writer from the LogFormatterParams struct

* split all logging tests into a separate file

* fixed formatting

[bugfix] Don't return the origin header when configured to * (gorilla…

…#116)

There's no reason to allow for a server to reflect all origin headers.
This has caused numerous security problems in the past.
 - cyu/rack-cors#126
 - https://nodesecurity.io/advisories/148
 - captncraig/cors@cc1cf75

Some helpful blog posts on the topic:
 - https://ejj.io/misconfigured-cors/
 - http://blog.portswigger.net/2016/10/exploiting-cors-misconfigurations-for.html

use http.StatusOK as initial value for responseLogger.status (gorilla…

…#103)

Merge pull request gorilla#94 from pavelnikolov/recovery-logger-inter…

…face-instead-of-struct

Use logger interface in recovery handler (gorilla#92)

Merge pull request gorilla#63 from saranrapjs/cors-custom-origins

[feature] Export OriginValidator for documentation purposes.