Switch to new vendor directory layout

Fixes #113

Signed-off-by: Marcos Lilljedahl <marcosnils@gmail.com>

vendor/github.com/opencontainers/specs/schema/Makefile

@@ -0,0 +1,15 @@
+
+default: help
+
+help:
+	@echo "Usage: make <target>"
+	@echo
+	@echo " * 'fmt' - format the json with indentation"
+	@echo " * 'validate' - build the validation tool"
+
+fmt:
+	for i in *.json ; do jq --indent 4 -M . "$${i}" > xx && cat xx > "$${i}" && rm xx ; done
+
+validate: validate.go
+	go build ./validate.go
+