Add support for building OCI multi-arch images

Signed-off-by: Rodrigo Menezes <brdude@gmail.com>

fix go.sum

wording

fix

go.mod

@@ -3,30 +3,29 @@ module github.com/concourse/oci-build-task
 go 1.12
 
 require (
-	github.com/BurntSushi/toml v0.3.1
+	github.com/Azure/azure-sdk-for-go v42.3.0+incompatible // indirect
+	github.com/Azure/go-autorest/autorest v0.10.2 // indirect
+	github.com/Azure/go-autorest/autorest/validation v0.2.0 // indirect
+	github.com/BurntSushi/toml v0.4.1
 	github.com/VividCortex/ewma v1.1.1 // indirect
 	github.com/concourse/go-archive v1.0.1
-	github.com/containerd/stargz-snapshotter/estargz v0.0.0-20210105085455-7f45f7438617 // indirect
-	github.com/docker/cli v20.10.2+incompatible // indirect
-	github.com/docker/docker v20.10.2+incompatible // indirect
-	github.com/fatih/color v1.10.0
-	github.com/golang/protobuf v1.4.3 // indirect
-	github.com/google/go-containerregistry v0.3.0
+	github.com/containerd/containerd v1.3.0 // indirect
+	github.com/coreos/bbolt v1.3.2 // indirect
+	github.com/fatih/color v1.13.0
+	github.com/google/go-containerregistry v0.9.0
+	github.com/googleapis/gnostic v0.2.2 // indirect
 	github.com/julienschmidt/httprouter v1.3.0
-	github.com/onsi/gomega v1.10.3 // indirect
-	github.com/opencontainers/image-spec v1.0.2-0.20190823105129-775207bd45b6 // indirect
+	github.com/maxbrunsfeld/counterfeiter/v6 v6.2.2 // indirect
 	github.com/pkg/errors v0.9.1
-	github.com/sirupsen/logrus v1.7.0
-	github.com/stretchr/testify v1.6.1
+	github.com/prometheus/tsdb v0.7.1 // indirect
+	github.com/sirupsen/logrus v1.8.1
+	github.com/stretchr/testify v1.7.0
 	github.com/u-root/u-root v7.0.0+incompatible
+	github.com/ugorji/go v1.1.4 // indirect
 	github.com/vbauerster/mpb v3.4.0+incompatible
+	github.com/vdemeester/k8s-pkg-credentialprovider v1.18.1-0.20201019120933-f1d16962a4db // indirect
 	github.com/vrischmann/envconfig v1.3.0
-	golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad // indirect
-	golang.org/x/net v0.0.0-20201224014010-6772e930b67b // indirect
-	golang.org/x/sys v0.0.0-20210108172913-0df2131ae363 // indirect
-	golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf // indirect
-	google.golang.org/protobuf v1.25.0 // indirect
-	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 	gotest.tools/v3 v3.0.3 // indirect
+	k8s.io/code-generator v0.17.2 // indirect
 )