Forcing namespace on Moped::BSON

[Fixes #165]
Fix broken spec on Ruby 2
Update README
Fix let warnings
Add yaml require
Add new authorization code to auth check in reply

[ fix #169 ]
Add additional not master checks in rs reconfig.

[ fix #168 ]
Update changelog
Bump version
Set refreshed_at even if node is still down.

This is to avoid checking down nodes with every query if the ismaster
command times out.

[ fix #173 ]
Adds checking for the word 'unauthorized' to the unauthorized check. #171
Refactor error message check in reply
merged