Unable to install flashback replay module on Ubuntu

[TJ]

Steps:

• Checkout this repo
• go get github.com/ParsePlatform/flashback/cmd/flashback

ubuntu@ip-172-31-24-xxx:~/flashback/cmd/flashback$ go get github.com/ParsePlatform/flashback/cmd/flashback
# github.com/mongodb/mongo-tools/common/json
../../../gocode/src/github.com/mongodb/mongo-tools/common/json/encode.go:245: undefined: sync.Pool

Environment:

ubuntu@ip-172-31-24-xxx:~/flashback$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 14.04.2 LTS
Release:    14.04
Codename:   trusty

[Travis Redman]

Are you using at least go version 1.4?

$ go version
go version go1.4.2 linux/amd64