no able to run go test program after installing go lang

I am getting the below error when trying to run a test written in Go. I have Golang and dep installed. I am new to Go and I am not sure what the issue is here.. Can someone please help me out?

xxxx-dxxxx:test xxxx$ go test
# _/Users/xxxx/dev/xxxx/test/xxxx/test
application_cluster_test.go:10:2: cannot find package "github.com/stretchr/testify/assert" in any of:
        /usr/local/Cellar/go/1.10.3/libexec/src/github.com/stretchr/testify/assert (from $GOROOT)
        /Users/xxxx/go/src/github.com/stretchr/testify/assert (from $GOPATH)
FAIL    _/Users/xxxx/dev/xxxx/test/xxxx/test [setup failed]