Add pull-{pushable,streams}, cleanup commonjs exports

pull-stream/index.d.ts

@@ -0,0 +1,16 @@
+// Type definitions for pull-stream 3.6.8
+// Project: https://github.com/pull-stream/pull-stream
+// Definitions by: Jaco Greeff <https://github.com/jacogr>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+/// <reference types="node"/>
+
+type Pull = {
+    (source: any, sink: any): void;
+
+    collect: (cb: (error: Error | null, values: Array<Buffer>) => any) => void,
+    drain: (handler: (message: Buffer) => void, errorHandler?: () => boolean) => void;
+    values: (values: Array<string | Buffer>) => void;
+};
+
+export = Pull;