Update test matrix to cover go1.15, go1.16, and go1.17

.travis.yml

@@ -1,13 +1,13 @@
 language: go
 
 go:
-  - "1.12"
-  - "1.13"
-  - "1.14"
+  - "1.15"
+  - "1.16"
+  - "1.17"
 
 before_install:
   - go get github.com/mattn/goveralls
   - go get golang.org/x/tools/cover
 
 script:
-  - $HOME/gopath/bin/goveralls -service=travis-ci -package github.com/go-test/deep
+  - $HOME/gopath/bin/goveralls -service=travis-pro -package github.com/go-test/deep

README.md

@@ -1,6 +1,6 @@
 # Deep Variable Equality for Humans
 
-[![Go Report Card](https://goreportcard.com/badge/github.com/go-test/deep)](https://goreportcard.com/report/github.com/go-test/deep) [![Build Status](https://travis-ci.org/go-test/deep.svg?branch=master)](https://travis-ci.org/go-test/deep) [![Coverage Status](https://coveralls.io/repos/github/go-test/deep/badge.svg?branch=master)](https://coveralls.io/github/go-test/deep?branch=master) [![GoDoc](https://godoc.org/github.com/go-test/deep?status.svg)](https://pkg.go.dev/github.com/go-test/deep?tab=doc)
+[![Go Report Card](https://goreportcard.com/badge/github.com/go-test/deep)](https://goreportcard.com/report/github.com/go-test/deep) [![Build Status](https://app.travis-ci.com/go-test/deep.svg?branch=master)](https://app.travis-ci.com/go-test/deep) [![Coverage Status](https://coveralls.io/repos/github/go-test/deep/badge.svg?branch=master)](https://coveralls.io/github/go-test/deep?branch=master) [![GoDoc](https://godoc.org/github.com/go-test/deep?status.svg)](https://pkg.go.dev/github.com/go-test/deep)
 
 This package provides a single function: `deep.Equal`. It's like [reflect.DeepEqual](http://golang.org/pkg/reflect/#DeepEqual) but much friendlier to humans (or any sentient being) for two reason:
 

go.mod

@@ -1,3 +1,3 @@
 module github.com/go-test/deep
 
-go 1.13
+go 1.16