vendor test tools in submodule

Instead of using the main module we should vendor the test tools in a
different directory. That way we do not add extra dependencies to the
main module which can be problemetic for packages or other users.

This is already done in buildah so this makes us more consitent.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

test/tools/vendor/github.com/vbatts/git-validation/rules/dco/dco.go

@@ -0,0 +1,51 @@
+package dco
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/vbatts/git-validation/git"
+	"github.com/vbatts/git-validation/validate"
+)
+
+func init() {
+	validate.RegisterRule(DcoRule)
+}
+
+var (
+	// ValidDCO is the regexp for signed off DCO
+	ValidDCO = regexp.MustCompile(`^Signed-off-by: ([^<]+) <([^<>@]+@[^<>]+)>$`)
+	// DcoRule is the rule being registered
+	DcoRule = validate.Rule{
+		Name:        "DCO",
+		Description: "makes sure the commits are signed",
+		Run:         ValidateDCO,
+		Default:     true,
+	}
+)
+
+// ValidateDCO checks that the commit has been signed off, per the DCO process
+func ValidateDCO(r validate.Rule, c git.CommitEntry) (vr validate.Result) {
+	vr.CommitEntry = c
+	if len(strings.Split(c["parent"], " ")) > 1 {
+		vr.Pass = true
+		vr.Msg = "merge commits do not require DCO"
+		return vr
+	}
+
+	hasValid := false
+	for _, line := range strings.Split(c["body"], "\n") {
+		if ValidDCO.MatchString(line) {
+			hasValid = true
+		}
+	}
+	if !hasValid {
+		vr.Pass = false
+		vr.Msg = "does not have a valid DCO"
+	} else {
+		vr.Pass = true
+		vr.Msg = "has a valid DCO"
+	}
+
+	return vr
+}