RiotWatcher.get_summoner fix

Since get_summoner relies on get_summoners output, it failed when the literal name was used to index into the returned dictionary. The dictionary returned by get_summoners lowered the input name and removed spaces. I just added a string replace to remove spaces and lowered the text. 

No clue how more exotic characters interact with the api but this should fix some of the more minor ones.
Merge pull request #11 from Zamubafoo/patch-1

RiotWatcher.get_summoner() fix