Add support for storage.conf and storage-config.5.md from github container storage package

Bump to the latest version of skopeo
vendor.conf: add ostree-go
      it is used by containers/image for pulling images to the OSTree storage.
fail early when image os does not match host os
Improve documentation on what to do with containers/image failures in test-skopeo
  We now have the docker-archive: transport
  Integration tests with built registries also exist
Support /etc/docker/certs.d
update image-spec to v1.0.0-rc6

ostree.patch

@@ -0,0 +1,39 @@
+diff --git a/vendor/github.com/ostreedev/ostree-go/pkg/otbuiltin/commit.go b/vendor/github.com/ostreedev/ostree-go/pkg/otbuiltin/commit.go
+index 7842cf9..9550f80 100644
+--- a/vendor/github.com/ostreedev/ostree-go/pkg/otbuiltin/commit.go
++++ b/vendor/github.com/ostreedev/ostree-go/pkg/otbuiltin/commit.go
+@@ -222,7 +222,7 @@ func (repo *Repo) Commit(commitPath, branch string, opts commitOptions) (string,
+ 		filter_data.skip_list = (*C.GHashTable)(skipList.Ptr())
+ 		C._set_owner_uid((C.guint32)(options.OwnerUID))
+ 		C._set_owner_gid((C.guint32)(options.OwnerGID))
+-		modifier = C._ostree_repo_commit_modifier_new_wrapper(flags, &filter_data, nil)
++		modifier = C._ostree_repo_commit_modifier_new_wrapper(flags, C.gpointer(&filter_data), nil)
+ 	}
+ 
+ 	if strings.Compare(options.Parent, "") != 0 {
+@@ -245,7 +245,7 @@ func (repo *Repo) Commit(commitPath, branch string, opts commitOptions) (string,
+ 	if len(commitPath) == 0 && (len(options.Tree) == 0 || len(options.Tree[0]) == 0) {
+ 		currentDir := (*C.char)(C.g_get_current_dir())
+ 		objectToCommit = glib.ToGFile(unsafe.Pointer(C.g_file_new_for_path(currentDir)))
+-		C.g_free(currentDir)
++		C.g_free(C.gpointer(currentDir))
+ 
+ 		if !glib.GoBool(glib.GBoolean(C.ostree_repo_write_directory_to_mtree(repo.native(), (*C.GFile)(objectToCommit.Ptr()), mtree, modifier, cancellable, &cerr))) {
+ 			goto out
+@@ -469,14 +469,14 @@ func handleStatOverrideLine(line string, table *glib.GHashTable) error {
+ 	}
+ 
+ 	modeAdd = (C.guint)(C.g_ascii_strtod((*C.gchar)(C.CString(line)), nil))
+-	C.g_hash_table_insert((*C.GHashTable)(table.Ptr()), C.g_strdup((*C.gchar)(C.CString(line[space+1:]))), C._guint_to_pointer(modeAdd))
++	C.g_hash_table_insert((*C.GHashTable)(table.Ptr()), C.gpointer(C.g_strdup((*C.gchar)(C.CString(line[space+1:])))), C._guint_to_pointer(modeAdd))
+ 
+ 	return nil
+ }
+ 
+ // Handle an individual line from a Skiplist file
+ func handleSkipListline(line string, table *glib.GHashTable) error {
+-	C.g_hash_table_add((*C.GHashTable)(table.Ptr()), C.g_strdup((*C.gchar)(C.CString(line))))
++	C.g_hash_table_add((*C.GHashTable)(table.Ptr()), C.gpointer( C.g_strdup((*C.gchar)(C.CString(line)))))
+ 
+ 	return nil
+ }

skopeo.spec

@@ -41,7 +41,7 @@ URL:            https://%{provider_prefix}
 Source0:        https://github.com/mtrmac/skopeo/archive/%{commit}/%{repo}-%{shortcommit}.tar.gz
 Source1:        storage.conf
 Source2:        storage.conf.5.md
-
+Patch:          ostree.patch
 
 %if 0%{?fedora}
 BuildRequires: go-srpm-macros