Bug 1325348 - mochitest-media jobs failing as we need pywin32 package available. r=grenade

MozReview-Commit-ID: FguOHuckMsg

testing/mozharness/configs/unittests/win_taskcluster_unittest.py

@@ -25,6 +25,7 @@ config = {
     "installer_path": INSTALLER_PATH,
     "binary_path": BINARY_PATH,
     "xpcshell_name": XPCSHELL_NAME,
+    "virtualenv_modules": ['pypiwin32'],
     "virtualenv_path": 'venv',
     "virtualenv_python_dll": os.path.join(os.path.dirname(sys.executable), "python27.dll"),