Forward custom headers (stripe#188)

* initCommit

* sanitize input and check for empty values

* regex sanitization

* clean up code

* Update pkg/cmd/listen.go

Co-Authored-By: Olivier Bellone <[email protected]>

* Update pkg/cmd/listen.go

Co-Authored-By: Olivier Bellone <[email protected]>

* Update pkg/proxy/endpoint.go

Co-Authored-By: Olivier Bellone <[email protected]>

* trigger linter

* remove print statements

fix trailing null bytes issue in uname (stripe#183)

Fix .gitignore

Print login URL when failing to open browser (stripe#160)

Disable function length (stripe#155)

Implement fixtures functionality (stripe#140)

* Implement basic fixtures functionality

* Parse params into url variables

* Write env file from fixtures

* Add current time of fixture request

* Use a new template style

* Refactor fixtures slightly to control when specific actions happen

* Restructure NewFixture and have an exclude field for metadata

Add --livemode flag to `listen` and `logs tail` commands (stripe#145)

Fix a few samples bugs that happened after merging (stripe#139)

* Fix a few samples bugs that happened after merging

* Fix alias to existing publishable key

Fix global api key and device name flags (stripe#137)

Write publishable key during login (stripe#133)

* Write publishable key during login

* Change where we set the config file

* Fix broken test now that we return an error

* Change global viper and reset it