Cannot find Package Error

Hi there, 
I was going through your code. However , i am not able to run the go code. 

When i run :  go build -o gochain

ERROR:

main.go:6:5: cannot find package "github.com/crisadamo/gochain" in any of:
	/usr/local/go/src/github.com/crisadamo/gochain (from $GOROOT)
	($GOPATH not set

Please mind that i have just started with this technology. Kindly Help. 
Good Day! 