Add gsutil 4.13 to telemetry/third_party

tools/telemetry/third_party/gsutil/third_party/boto/CONTRIBUTING

+============
+Contributing
+============
+
+For more information, please see the official contribution docs at
+http://docs.pythonboto.org/en/latest/contributing.html.
+
+
+Contributing Code
+=================
+
+* A good patch:
+
+  * is clear.
+  * works across all supported versions of Python.
+  * follows the existing style of the code base (PEP-8).
+  * has comments included as needed.
+
+* A test case that demonstrates the previous flaw that now passes
+  with the included patch.
+* If it adds/changes a public API, it must also include documentation
+  for those changes.
+* Must be appropriately licensed (New BSD).
+
+
+Reporting An Issue/Feature
+==========================
+
+* Check to see if there's an existing issue/pull request for the
+  bug/feature. All issues are at https://github.com/boto/boto/issues
+  and pull reqs are at https://github.com/boto/boto/pulls.
+* If there isn't an existing issue there, please file an issue. The ideal
+  report includes:
+
+  * A description of the problem/suggestion.
+  * How to recreate the bug.
+  * If relevant, including the versions of your:
+
+    * Python interpreter
+    * boto
+    * Optionally of the other dependencies involved
+
+  * If possible, create a pull request with a (failing) test case demonstrating
+    what's wrong. This makes the process for fixing bugs quicker & gets issues
+    resolved sooner.
+
+