Update to gopkg.in/yaml.v3

Trying to reduce the size of Podman by eliminating the need for v2 of
this library. This repo is one of the last v2 holdouts.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

go.mod

@@ -4,5 +4,5 @@ go 1.12
 
 require (
 	github.com/davecgh/go-spew v1.1.1
-	gopkg.in/yaml.v2 v2.4.0
+	gopkg.in/yaml.v3 v3.0.1
 )

go.sum

@@ -2,5 +2,5 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
-gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

yaml.go

@@ -24,7 +24,7 @@ import (
 	"reflect"
 	"strconv"
 
-	"gopkg.in/yaml.v2"
+	"gopkg.in/yaml.v3"
 )
 
 // Marshal marshals obj into JSON using stdlib json.Marshal, and then converts JSON to YAML using JSONToYAML (see that method for more reference)

yaml_test.go

@@ -26,7 +26,7 @@ import (
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
-	yaml "gopkg.in/yaml.v2"
+	yaml "gopkg.in/yaml.v3"
 )
 
 /* Test helper functions */