[function.checkType]: rename file according to function name

src/function/index.js

@@ -2,7 +2,7 @@
  * @namespace function
  */
 export { default as argsToArray } from './argsToArray';
-export { default as checkTypes } from './checkTypes';
+export { default as checkTypes } from './checkType';
 export { default as combine } from './combine';
 export { default as curry } from './curry';
 export { default as debounce } from './debounce';