[is-promise] add linting (#18865)

types/is-promise/index.d.ts

@@ -1,8 +1,8 @@
-// Type definitions for is-promise
+// Type definitions for is-promise 2.1
 // Project: https://github.com/then/is-promise
 // Definitions by: Daniel Rosenwasser <https://github.com/DanielRosenwasser>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 export = isPromise;
 
-declare function isPromise(obj: any): obj is PromiseLike<any>;
+declare function isPromise(obj: any): obj is PromiseLike<any>;

types/is-promise/is-promise-tests.ts

@@ -1,15 +1,14 @@
 import isPromise = require("is-promise");
 
-isPromise({ then() { }});
+isPromise({ then() {} });
 isPromise(null);
-isPromise({ });
+isPromise({});
 isPromise({then: true});
 
 function f(x: number | PromiseLike<number>) {
     if (isPromise(x)) {
         x.then;
-    }
-    else {
+    } else {
         x.toExponential;
     }
-}
+}

types/is-promise/tslint.json

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