Trim doc block annotations after parsing

Summary:
Trims doc block annotations. This mitigates problems with leading and trailing spaces in `providesModule` annotations.

This module doesn’t have tests, but it is exclusively used for `providesModule` annotations right now.

Reviewed By: mjesun

Differential Revision: D5319814

fbshipit-source-id: de55df5b4b199738f9b01151eb86f3c863485b15

packages/metro-bundler/src/node-haste/DependencyGraph/docblock.js

@@ -56,7 +56,7 @@ function parse(docblock: string): Array<[string, string]> {
   var result = [];
   var match;
   while ((match = propertyRe.exec(docblock))) {
-    result.push([match[1], match[2]]);
+    result.push([match[1], match[2].trim()]);
   }
 
   return result;