Improve READMEs
roshi-server: implement README
common: implement README
Feedback from Björn
roshi-server: remove dead code
roshi-server: supply explicit quorum; rename flags
.travis.yml: give Redis some time to start
Merge pull request #6 from soundcloud/explicit-quorum

roshi-server: supply explicit quorum; rename flags
Clarify references to quorum.
Merge pull request #4 from soundcloud/improve-readmes

Improve READMEs
Solved merge conflicts.