Fixing ELB unit tests.  Also did some PEP8 cleanup on ELB code.
elasticache module: add backward-compatible support for Python 3.3+
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.
Merge pull request #2356 from felixonmars/elasticache-py3

elasticache module: add backward-compatible support for Python 3.3+. Fixes #2356.