ross/requests-futures — pull request #10 by mkai (2013-10-26 17:11:27+00:00)
Title: Set connection pool size equal to max_workers if needed

When making more than 10 requests (and max_workers set accordingly) at once, I got the following warning:

```
HttpConnectionPool is full, discarding connection:
```

This patch adjusts the size of the HTTP connection pool in FuturesSession to `max_workers` or `executor._max_workers` if needed.