Add badges to the README

Author: cjslep

README.md

@@ -1,5 +1,11 @@
 # httpsig
 
+> HTTP Signatures made simple
+
+[![Build Status][Build-Status-Image]][Build-Status-Url] [![Go Reference][Go-Reference-Image]][Go-Reference-Url]
+[![Go Report Card][Go-Report-Card-Image]][Go-Report-Card-Url] [![License][License-Image]][License-Url]
+[![OpenCollective][OpenCollective-Image]][OpenCollective-Url]
+
 `go get github.com/go-fed/httpsig`
 
 Implementation of [HTTP Signatures](https://tools.ietf.org/html/draft-cavage-http-signatures).
@@ -92,3 +98,14 @@ func verify(r *http.Request) error {
 `Verifier`s are not safe for concurrent use by goroutines, but since they are
 constructed on a per-request or per-response basis it should not be a common
 restriction.
+
+[Build-Status-Image]: https://travis-ci.org/go-fed/httpsig.svg?branch=master
+[Build-Status-Url]: https://travis-ci.org/go-fed/httpsig
+[Go-Reference-Image]: https://pkg.go.dev/badge/github.com/go-fed/httpsig
+[Go-Reference-Url]: https://pkg.go.dev/github.com/go-fed/httpsig
+[Go-Report-Card-Image]: https://goreportcard.com/badge/github.com/go-fed/httpsig
+[Go-Report-Card-Url]: https://goreportcard.com/report/github.com/go-fed/httpsig
+[License-Image]: https://img.shields.io/github/license/go-fed/httpsig?color=blue
+[License-Url]: https://opensource.org/licenses/BSD-3-Clause
+[OpenCollective-Image]: https://img.shields.io/opencollective/backers/go-fed-activitypub-labs
+[OpenCollective-Url]: https://opencollective.com/go-fed-activitypub-labs