make sure node_version is set, test for caching output

bin/compile

@@ -35,6 +35,7 @@ else
 
   if test $default_satisfies; then
     status "Using latest stable node version $stable_version"
+    node_version=$stable_version
   else
     # Find all available versions from nodejs.org/dist
     args=""

bin/test

@@ -54,6 +54,7 @@ testProfileCreated() {
 testNodeModulesCached() {
   cache=$(mktmpdir)
   compile "node-modules-caching" $cache
+  assertCaptured "Caching node_modules for future builds"
   assertEquals "1" "$(ls -1 $cache/node_modules/0.10.18 | wc -l)"
 }