add OpenapiType for BTreeSet and HashSet

gotham_restful/src/openapi/types.rs

@@ -9,6 +9,7 @@ use openapiv3::{
 };
 #[cfg(feature = "uuid")]
 use uuid::Uuid;
+use std::collections::{BTreeSet, HashSet};
 
 /**
 This struct needs to be available for every type that can be part of an OpenAPI Spec. It is
@@ -273,6 +274,22 @@ impl<T : OpenapiType> OpenapiType for Vec<T>
 	}
 }
 
+impl<T : OpenapiType> OpenapiType for BTreeSet<T>
+{
+	fn schema() -> OpenapiSchema
+	{
+		<Vec<T> as OpenapiType>::schema()
+	}
+}
+
+impl<T : OpenapiType> OpenapiType for HashSet<T>
+{
+	fn schema() -> OpenapiSchema
+	{
+		<Vec<T> as OpenapiType>::schema()
+	}
+}
+
 #[cfg(feature = "chrono")]
 str_types!(format = Date, Date<FixedOffset>, Date<Local>, Date<Utc>, NaiveDate);
 #[cfg(feature = "chrono")]