support draft releases for in and out

* in will pull in the latest release, even if draft. It will not create
  the files `tag` and `version`, if no tag is defined on the draft
  release.
* out will push a release in a draft state when provided as a param

[#102513822]

Signed-off-by: David Morhovich <dmorhovich@pivotal.io>

resources.go

@@ -40,6 +40,7 @@ type OutParams struct {
 	BodyPath      string `json:"body"`
 	TagPath       string `json:"tag"`
 	CommitishPath string `json:"commitish"`
+	Draft         bool   `json:"draft"`
 
 	Globs []string `json:"globs"`
 }