Support custom scheduler and RPC responder.  Factor out code smell in luigi.server.  Revive remote scheduler test.  Add test-generated files to .gitignore.
Remove pep8 warnings from luigi.worker module

Still has some warnings, but they are long messages (>80)
Merge pull request #86 from spotify/lallea/custom_scheduler

Support custom scheduler and API responder.
Merge pull request #88 from freyes/upstream

Remove pep8 warnings from luigi.worker module
Merge pull request #87 from freyes/d64b2aa26648bb514c51c0aa76c9627078bde081

Add tox support to run test suite
Merge remote-tracking branch 'upstream/master'