Add Apple M1 Build Arch (& other arm64) (#28)

* Update `gox` call in the Makefile to:
    * include arch: arm64
    * remove arch: 386
    * Explicitly include `-osarch="linux/386" -osarch="windows/386`
* Specify Go v1.16 in CI config
* add a go.mod
* Add a comment to exported Replacement struct
* gofmt -s -w search-replace_test.go

.travis.yml

@@ -1,7 +1,7 @@
 language: go
 
 go:
-    - 1.13.x
+    - 1.16.x
     - master
 
 install:

Makefile

@@ -5,7 +5,7 @@ all: vet fmt lint test build
 
 build: clean
 	which gox > /dev/null || go get -u github.com/mitchellh/gox
-	gox -os="linux" -os="darwin" -os="windows" -arch="amd64" -arch="386" -output="${BUILDDIR}/${BINARY}_{{.OS}}_{{.Arch}}"
+	gox -os="darwin" -os="linux" -os="windows" -arch="amd64" -arch="arm64" -osarch="linux/386" -osarch="windows/386" -output="${BUILDDIR}/${BINARY}_{{.OS}}_{{.Arch}}"
 	gzip build/*
 
 vet:

go.mod

@@ -0,0 +1,3 @@
+module github.com/automattic/go-search-replace
+
+go 1.16

search-replace.go

@@ -32,6 +32,7 @@ var (
 	bad     = regexp.MustCompile(badInputRe)
 )
 
+// Replacement has two fields (both byte slices): "From" & "To"
 type Replacement struct {
 	From []byte
 	To   []byte

search-replace_test.go

@@ -18,7 +18,7 @@ func BenchmarkSimpleReplace(b *testing.B) {
 	to := []byte("https:")
 	for i := 0; i < b.N; i++ {
 		replaceAndFix(&line, []*Replacement{
-			&Replacement{
+			{
 				From: from,
 				To:   to,
 			},
@@ -32,7 +32,7 @@ func BenchmarkSerializedReplace(b *testing.B) {
 	to := []byte("https://automattic.com")
 	for i := 0; i < b.N; i++ {
 		replaceAndFix(&line, []*Replacement{
-			&Replacement{
+			{
 				From: from,
 				To:   to,
 			},
@@ -98,7 +98,7 @@ func TestReplace(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.testName, func(t *testing.T) {
 			replaced := replaceAndFix(&test.in, []*Replacement{
-				&Replacement{
+				{
 					From: test.from,
 					To:   test.to,
 				},
@@ -123,11 +123,11 @@ func TestMultiReplace(t *testing.T) {
 			in:       []byte("http://automattic.com"),
 			out:      []byte("https://automattic.org"),
 			replacements: []*Replacement{
-				&Replacement{
+				{
 					From: []byte("http:"),
 					To:   []byte("https:"),
 				},
-				&Replacement{
+				{
 					From: []byte("automattic.com"),
 					To:   []byte("automattic.org"),
 				},
@@ -138,11 +138,11 @@ func TestMultiReplace(t *testing.T) {
 			in:       []byte("http://automattic.com"),
 			out:      []byte("https://automattic.org"),
 			replacements: []*Replacement{
-				&Replacement{
+				{
 					From: []byte("http:"),
 					To:   []byte("https:"),
 				},
-				&Replacement{
+				{
 					From: []byte("//automattic.com"),
 					To:   []byte("//automattic.org"),
 				},