Add pyramid_redis_sessions dev dependency

Needed to build the Chrome extension with production.ini

setup.py

@@ -72,7 +72,7 @@ def run_tests(self):
]

DEV_EXTRAS = ['pyramid_debugtoolbar>=2.1', 'prospector[with_pyroma]', 'pep257',
              'sphinxcontrib-httpdomain']
              'sphinxcontrib-httpdomain', 'pyramid_redis_sessions']
TESTING_EXTRAS = ['mock', 'pytest>=2.5', 'pytest-cov', 'factory-boy']
CLAIM_EXTRAS = ['mandrill']
YAML_EXTRAS = ['PyYAML']