Fix koa-compose typings

This changes ComposedMiddleware take next as a parameterless async function.

Also, add tslint.json and fix lint errors.

koa-compose/index.d.ts

@@ -8,7 +8,7 @@ declare function compose<T>(middleware: Array<compose.Middleware<T>>): compose.C
 
 declare namespace compose {
     type Middleware<T> = (context: T, next: () => Promise<any>) => any;
-    type ComposedMiddleware<T> = (context: T, next?: Middleware<T>) => Promise<void>;
+    type ComposedMiddleware<T> = (context: T, next?: () => Promise<any>) => Promise<void>;
 }
 
 export = compose;

koa-compose/koa-compose-tests.ts

@@ -1,17 +1,15 @@
 
 import compose = require('koa-compose');
 
-var fn1: compose.Middleware<any> = function(context: any, next: () => Promise<void>): Promise<any> {
-    return Promise
+var fn1: compose.Middleware<any> = (context: any, next: () => Promise<void>): Promise<any> =>
+    Promise
         .resolve(console.log('in fn1'))
         .then(() => next());
-};
 
-var fn2: compose.Middleware<any> = function(context: any, next: () => Promise<void>): Promise<any> {
-    return Promise
+var fn2: compose.Middleware<any> = (context: any, next: () => Promise<void>): Promise<any> =>
+    Promise
         .resolve(console.log('in fn2'))
         .then(() => next());
-};
 
 
 var fn = compose([fn1, fn2]);

koa-compose/tslint.json

@@ -0,0 +1 @@
+{ "extends": "../tslint.json" }