Update vendoring as well as libcompose

This commit updates libcompose in order to merge in
https://github.com/docker/libcompose/pull/423 which affected
https://github.com/kubernetes-incubator/kompose/issues/92 by not
erroring out when an image name wasn't provided.

Closes https://github.com/kubernetes-incubator/kompose/issues/92

As well as knocks out the last required milestone for a 0.2.1 release
https://github.com/kubernetes-incubator/kompose/milestone/2

vendor/github.com/xeipuuv/gojsonschema/errors.go

@@ -2,10 +2,18 @@ package gojsonschema
 
 import (
 	"bytes"
+	"sync"
 	"text/template"
 )
 
-var errorTemplates *template.Template
+var errorTemplates errorTemplate = errorTemplate{template.New("errors-new"),sync.RWMutex{}}
+
+// template.Template is not thread-safe for writing, so some locking is done
+// sync.RWMutex is used for efficiently locking when new templates are created
+type errorTemplate struct {
+	*template.Template
+	sync.RWMutex
+}
 
 type (
 	// RequiredError. ErrorDetails: property string
@@ -241,14 +249,17 @@ func formatErrorDescription(s string, details ErrorDetails) string {
 	var descrAsBuffer bytes.Buffer
 	var err error
 
-	if errorTemplates == nil {
-		errorTemplates = template.New("all-errors")
-	}
-
+	errorTemplates.RLock()
 	tpl = errorTemplates.Lookup(s)
+	errorTemplates.RUnlock()
+
 	if tpl == nil {
+		errorTemplates.Lock()
 		tpl = errorTemplates.New(s)
+
 		tpl, err = tpl.Parse(s)
+		errorTemplates.Unlock()
+
 		if err != nil {
 			return err.Error()
 		}

vendor/github.com/xeipuuv/gojsonschema/jsonLoader.go

@@ -101,7 +101,9 @@ func (l *jsonReferenceLoader) JsonReference() (gojsonreference.JsonReference, er
 }
 
 func (l *jsonReferenceLoader) LoaderFactory() JSONLoaderFactory {
-	return &DefaultJSONLoaderFactory{}
+	return &FileSystemJSONLoaderFactory{
+		fs: l.fs,
+	}
 }
 
 // NewReferenceLoader returns a JSON reference loader using the given source and the local OS file system.