ensure-go-installed is meant to be sourced, not executed

Rename it and make it non-executable to prevent confusion.

script/bootstrap

@@ -10,7 +10,7 @@ export GOPATH="$ROOTDIR/.gopath"
 if [[ "$(uname -s)" = "Darwin" ]]; then
     brew bundle
 fi
-script/ensure-go-installed
+. script/ensure-go-installed.sh
 
 go get -u github.com/golang/dep/cmd/dep
 

script/ensure-go-installed.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+# This file is meant to be sourced.
 
 ROOTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )/.." && pwd )"
 

script/go

@@ -3,7 +3,7 @@
 set -e
 
 export ROOTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )/.." && pwd )"
-. $ROOTDIR/script/ensure-go-installed
+. $ROOTDIR/script/ensure-go-installed.sh
 export GOPATH=$ROOTDIR/.gopath
 
 exec "$(basename $0)" "$@"