Add an autorequires on ruby-json

mongo_replset provider requires json library
for which this commit adds a autorequires
dependency.
Merge pull request #111 from pkilambi/master

Add an autorequires on ruby-json
Add tests for replsets
Raise error correctly on database timeout
Allow mongodb bind_ips to take a string
Update autorequires
Update replsets to have self.instances
Rewrite provider to use flush
Correct package name and logpath
fixup replset tests
Patch server test for tengen port changing being broken