build(typescript): path mapping now includes checking without an extension (#875)

Author: hansl

lib/broccoli/broccoli-typescript.js

@@ -391,8 +391,8 @@ class CustomLanguageServiceHost {
   resolveModuleNames(moduleNames, containingFile)/*: ResolvedModule[]*/ {
     return moduleNames.map((moduleName) => {
       let shouldResolveUsingDefaultMethod = false;
-      for (const ext of ['ts', 'd.ts']) {
-        const name = `${moduleName}.${ext}`;
+      for (const ext of ['', '.ts', '.d.ts']) {
+        const name = `${moduleName}${ext}`;
         const maybeModule = this._resolveModulePathWithMapping(name, containingFile);
         if (typeof maybeModule == 'string') {
           return {