Not resolving dependency in vendor directory

I'm running go1.6 and am getting the follow error when running "go build" in GOPATH (/Users/bweidlich/Projects/go)

main.go:6:2: cannot find package "github.com/spf13/viper" in any of:
/usr/local/go/src/github.com/spf13/viper (from $GOROOT)
/Users/bweidlich/Projects/go/src/github.com/spf13/viper (from $GOPATH)

Project structure:

bin/
glide.lock
glide.yaml
go.iml
logs/
main.go
pkg/
src/
vendor/
      github.com/
                 deckarep/gosx-notifier
                 spf13/viper
                 gizak/termui

main.go

package main

import (
    "fmt"
    "github.com/gizak/termui" <--- doesn't resolve
    "github.com/spf13/viper"  <--- doesn't resolve
    "log"
    "bweidlich/dash"
    "net/http"
    "os"
    "os/exec"
    "time"
)