Updates README installation procedure

Includes an installation workaround for the exception
'dist must be a Distribution instance'
Fix the configuration error handling
Adds check for swift_operator_role, else exit
Fix compatibilities issues with recent swift devel

Server does not set x-trans-id anymore
swift.common includes a more generic FileLikeIter object
Fix tests for new flake8 rules
Merge pull request #63 from TristanCacqueray/master

Maintenance fixes