Fixing ELB unit tests.  Also did some PEP8 cleanup on ELB code.
Remove use of six.b and just use byte literals.  Add elb unit tests to Py3 whitelist.
Merge pull request #2352 from garnaat/fix-elb-tests

Fixing ELB unit tests.  Also did some PEP8 cleanup on ELB code. Fixes #2352.