Add support for per-job middlewares.
Support a callback in RedisReconnect middleware so we can use it on a per-job basis.
We're not using phantomjs on travis, so disable it.

The travis build is failing with /home/travis/build.sh: line 128: phantomjs/bin/phantomjs: No such file or directory
Work around an rspec-mocks/1.9.2 issue by making a spec pending on 1.9.2.
Merge pull request #84 from seomoz/per_job_middleware

Per job middleware