In method get in class Svtplay: index dict streams by number
 instead of key for Python 3 compatibility.

In Python 2, dict.keys() returned a list but in Python 3 it returns a dict_keys
instance which is not indexable. Details: http://stackoverflow.com/questions/8953627/python-dictionary-keys-error

This patch should be compatible with both Python 2 and 3.
Merge pull request #18 from antoneliasson/master

In method get in class Svtplay: index dict streams by number instead of key for Python 3 compatibility.