Initial reference implementations for discoverd load balancing.

This commit includes Random and RoundRobin strategies.

Signed-off-by: Anthony Bishopric <git@anthonybishopric.com>
Merge pull request #24 from anthonybishopric/balancer_ref_impl

Initial reference implementations for load balancing
Test Go tip on travis with allowed failures

Signed-off-by: Jonathan Rudenberg <jonathan@titanous.com>