Added some additional validation so that any characters within a bean
name that doesn't conform to the librato api gets converted to an
underscore before being sent over to librato.  This should prevent
the API for throwing 400's for wonky bean names.  Looking at you
"kafka.server"!
Merge pull request #12 from rayrod2030/bugfix-11/clean-up-metric-names-for-posting-to-api

Added some additional validation so that any characters within a bean