requests updated to latest version (2.1.0) - fix #268

Update **requests** to the latest version fixes the issue #268: *ImportError: No module named pwd*

App Engine SDK 1.8.8 don't allow importing ``pwd`` since it's no longer available on the server, but now ``netrc `` import is inside the function ``get_netrc_auth(url)`` in ``utils.py`` which prevents the *import error* when starting a gae-boilerplate project:

```python
(...)
def get_netrc_auth(url):
    """Returns the Requests tuple auth for a given url from netrc."""

    try:
        from netrc import netrc, NetrcParseError

(...)
```
requests ``utils.py`` code [here] (https://github.com/kennethreitz/requests/blob/ba3dab5047946e3c832d1586613e92f69e9a865a/requests/utils.py#L71).