Fix: agent wasn't able to connect to Redis

When no password is given for the Redis server, the protocol (redis://) was missing from the constructed URL, which was resulting in failed parsing by the URI class.
refactoring example agent to use gem version 0.6.0.pre
additional fixes to gem updates
fixed improper command for creating a metric group
Merge pull request #2 from arikfr/patch-1

Fix: agent wasn't able to connect to Redis
Merge branch 'develop' of github.com:CopperEgg/revealmetrics-example-agent into feature/ares
Merge branch 'develop', remote-tracking branch 'origin' into feature/ares
better error handling
fixing invalid save method
notifying user of dashboard creation failure
reducing the number of requests to the API to retrieve dashboards and metric groups
updating gemfile for testing
specifying pre-release version of copperegg gem
Merge branch 'feature/ares' into develop