Allow additional arguments to be passed into hooks

If a packager wants to be able to support addititional arguments on his
hook this will allow them to setup the configuration with these arguments.

For example this would allow a hook developer to add support for a --debug
flag to change the level of debugging in his hook.

In order to complete this task, I had to vendor in the latest
github.com://opencontainers/runtime-tools, which caused me to have to fix a
Mount and Capability interface calls

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

vendor/github.com/opencontainers/runtime-tools/specerror/bundle.go

@@ -0,0 +1,29 @@
+package specerror
+
+import (
+	"fmt"
+
+	rfc2119 "github.com/opencontainers/runtime-tools/error"
+)
+
+// define error codes
+const (
+	// ConfigInRootBundleDir represents "This REQUIRED file MUST reside in the root of the bundle directory"
+	ConfigInRootBundleDir Code = 0xa001 + iota
+	// ConfigConstName represents "This REQUIRED file MUST be named `config.json`."
+	ConfigConstName
+	// ArtifactsInSingleDir represents "When supplied, while these artifacts MUST all be present in a single directory on the local filesystem, that directory itself is not part of the bundle."
+	ArtifactsInSingleDir
+)
+
+var (
+	containerFormatRef = func(version string) (reference string, err error) {
+		return fmt.Sprintf(referenceTemplate, version, "bundle.md#container-format"), nil
+	}
+)
+
+func init() {
+	register(ConfigInRootBundleDir, rfc2119.Must, containerFormatRef)
+	register(ConfigConstName, rfc2119.Must, containerFormatRef)
+	register(ArtifactsInSingleDir, rfc2119.Must, containerFormatRef)
+}