Fix 'isRelativeImport' to allow require('.') and require('..')

Summary:
davidaurelio 👍
Closes https://github.com/facebook/react-native/pull/10006

Differential Revision: D3898703

fbshipit-source-id: 6d88122ed56108d52bc1ae1b14c7ff7c39fd9b9a

packager/react-packager/src/node-haste/DependencyGraph/ResolutionRequest.js

@@ -533,7 +533,7 @@ function resolveKeyWithPromise([key, promise]) {
 }
 
 function isRelativeImport(path) {
-  return /^[.][.]?[/]/.test(path);
+  return /^[.][.]?(?:[/]|$)/.test(path);
 }
 
 module.exports = ResolutionRequest;