Drop official support for go 1.1
Merge pull request #203 from Shopify/drop-go-1.1

Drop official support for go 1.1
Add `go vet` as build step.
Merge pull request #195 from Shopify/govet

Add `go vet` as build step
Add errcheck to Travis build
Merge pull request #198 from Shopify/errcheck

Add errcheck to build
Add 1.4 to travis
Use go tip for now
.
.
:poop:
Add Replicas() and ReplicasInSync() to client

Switch the 'leader' hash to store the entire PartitionMetadata instead of just
the leaderID. After that quite straightforward.
add test
DRY up two functions
Merge pull request #208 from Shopify/expose-all-metadata

Expose all metadata
Merge pull request #205 from Shopify/go-1.4

Add 1.4 to travis
A few inline comments for producer-ng functions

Also credit myself for reference implementations of the two channel idioms that
I ended up using. Having https://github.com/eapache/channels/ already written
and at hand made it a lot easier to reason about the design when I started
building this.
Merge pull request #209 from Shopify/producer-comments-credit

A few inline comments for producer-ng functions
WIP