Backport changes from Cloudproxy (#11)

src/types.ts

@@ -0,0 +1,9 @@
+import { IncomingMessage, ServerResponse } from 'http';
+
+export interface RequestContext {
+  req: IncomingMessage
+  res: ServerResponse
+  startTimestamp: number
+  errorResponse: (msg: string) => void,
+  successResponse: (msg: string, extendedProperties?: object) => void
+}