glide.yaml: Drop runtime-spec

The last reference was removed with image/config.go.

Signed-off-by: W. Trevor King <[email protected]>

Author: wking

glide.yaml

@@ -1,9 +1,5 @@
 package: github.com/opencontainers/image-spec
 import:
-- package: github.com/opencontainers/runtime-spec
-  version: ^1.0.0-rc1
-  subpackages:
-  - specs-go
 - package: github.com/pkg/errors
   version: ">=0.7.0"
 - package: github.com/spf13/cobra