feat(http-spec): align IHttpService['security'] with IHttpOperation['security'] (#142)

BREAKING CHANGE: IHttpService['security'] is a 2D array now

Author: Jakub Rożek

src/http-spec.ts

@@ -11,7 +11,7 @@ export interface IHttpService extends INode, IShareableNode, ISpecExtensions {
   name: string;
   version: string;
   servers?: IServer[];
-  security?: HttpSecurityScheme[];
+  security?: HttpSecurityScheme[][];
   securitySchemes?: HttpSecurityScheme[];
   termsOfService?: string;
   contact?: {