updated setter for environment module to comply with JS standards

dist/npmci.env.d.ts

@@ -4,6 +4,7 @@ import { Dockerfile } from "./npmci.build.docker";
 export declare let repo: GitRepo;
 export declare let buildStage: string;
 export declare let dockerRegistry: string;
+export declare let setDockerRegistry: (dockerRegistryArg: string) => void;
 export declare let dockerFilesBuilt: Dockerfile[];
 export declare let dockerFiles: Dockerfile[];
 export declare let config: {