✨ Track sensitive variable keys to support JSON template writing

Signed-off-by: Brendan Devenney <brendan@devenney.io>

template/parse.go

@@ -60,6 +60,7 @@ func (r *rawTemplate) Template() (*Template, error) {
 	}
 	for k, rawV := range r.Variables {
 		var v Variable
+		v.Key = k
 
 		// Variable is required if the value is exactly nil
 		v.Required = rawV == nil

template/template.go

@@ -70,6 +70,7 @@ type Push struct {
 
 // Variable represents a variable within the template
 type Variable struct {
+	Key      string
 	Default  string
 	Required bool
 }