Convert input DSN values to strings (fixes GH-653)

CHANGES

@@ -5,6 +5,7 @@ Version 5.8.0
 * pkg_resources is now prioritized for default version detection.
 * Updated `in_app` support to include exception frames.
 * Fixed support for `SENTRY_USER_ATTRS` in Flask.
+* Handle DSNs which are sent as unicode values in Python 2.
 
 Version 5.7.2
 -------------

raven/conf/remote.py

@@ -5,6 +5,7 @@ import warnings
 from raven.exceptions import InvalidDsn
 from raven.transport.threaded import ThreadedHTTPTransport
 from raven.utils import six
+from raven.utils.encoding import to_string
 from raven.utils.urlparse import parse_qsl, urlparse
 
 ERR_UNKNOWN_SCHEME = 'Unsupported Sentry DSN scheme: {0} ({1})'
@@ -55,6 +56,7 @@ class RemoteConfig(object):
 
     @classmethod
     def from_string(cls, value, transport=None, transport_registry=None):
+        value = to_string(value)
         url = urlparse(value)
 
         if url.scheme not in ('http', 'https'):