Handle redirects ourselves so they are always signed

Requests 2.3 strips Authorization headers when redirects send requests
to URLs with different DNS names, which results in requests with no
Authorization headers at all.  We address this by switching off its
internal redirect handling.

Note that the means by which this is done does not exist in requests
1.1.

requestbuilder/service.py

@@ -177,7 +177,8 @@ class BaseService(RegionConfigurableMixin):
                         # See requests commit 325ea7b.
                         response = self.session.send(
                             p_request, stream=True, timeout=self.timeout,
-                            verify=self.session_args['verify'])
+                            verify=self.session_args['verify'],
+                            allow_redirects=False)
                     except requests.exceptions.Timeout:
                         if attempt_no < max_tries:
                             self.log.debug('timeout', exc_info=True)

requestbuilder/suite.py

@@ -30,7 +30,7 @@ class RequestBuilder(object):
 
     @staticmethod
     def format_version():
-        return 'requestbuilder {0} (Intermezzo)'.format(__version__)
+        return 'requestbuilder {0} (Allegro)'.format(__version__)
 
     @staticmethod
     def list_config_files():

setup.py

@@ -22,7 +22,7 @@ from setuptools import find_packages, setup
 from requestbuilder import __version__
 
 
-requirements = ['requests>=1',
+requirements = ['requests>=2.4',
                 'six']
 if sys.version_info < (2, 7):
     requirements.append('argparse')