Fix: Use of iterators in application setup

Previously, the application setup had two mistakes. First, the
url building required that service plugins use a list for urls.
Second, the dictionary building for converters used iteritems()
which no longer exists in py3.

To resolve these issues the iteritems() call has been replaced
with items() and the url building now uses chain to work with
any iterable.

Signed-off-by: Kevin Conway <kevinjacobconway@gmail.com>
Merge pull request #18 from kevinconway/py3_compat

Fix: Use of iterators in application setup