Fix import paths in subpackages

[epicfilemcnulty]

The repo was recently forked, but the import paths in subpackages files (store/consul/consul.go, store/redis/redis.go, etc) have not been updated and still point to docker/libkv. This lead to various compilation errors, for example:

# github.com/abronan/libkv/store/consul
/home/vlad/go/src/github.com/abronan/libkv/store/consul/consul.go:170:40: undefined: store.ReadOptions
/home/vlad/go/src/github.com/abronan/libkv/store/consul/consul.go:232:43: undefined: store.ReadOptions
/home/vlad/go/src/github.com/abronan/libkv/store/consul/consul.go:244:47: undefined: store.ReadOptions