Add 'requests' library to third_party.

third_party/requests/LICENSE

Index: third_party/requests/LICENSE
diff --git a/third_party/requests/LICENSE b/third_party/requests/LICENSE
new file mode 100644
index 0000000000000000000000000000000000000000..ca97ae0ead74791eed720be61d19497580cb4ad5
--- /dev/null
+++ b/third_party/requests/LICENSE
@@ -0,0 +1,13 @@
+Copyright 2013 Kenneth Reitz
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.