Handle bad symlinks properly

Regression introduced by pulling in glob as a dep, due to root cause
isaacs/node-glob#170.

Added good and bad symlinks to test, which would have caught this.

Fixes #65
Fixes ember-cli/ember-cli#3413

package.json

@@ -14,7 +14,7 @@
   },
   "bin": "./bin.js",
   "dependencies": {
-    "glob": "^4.4.1"
+    "glob": "^4.4.2"
   },
   "files": [
     "bin.js",

test/run.sh

@@ -5,6 +5,10 @@ for i in test-*.js; do
   echo -n $i ...
   bash setup.sh
   node $i
+  if [ $? -ne 0 ]; then
+    echo "fail"
+    code=1
+  fi
   if [ -d target ]; then
     echo "fail"
     code=1

test/setup.sh

@@ -27,6 +27,12 @@ fill () {
     let f--
   done
 
+  # valid symlink
+  ln -s "f-$depth-1" "$target/link-$depth-good"
+
+  # invalid symlink
+  ln -s "does-not-exist" "$target/link-$depth-bad"
+
   let depth--
 
   if [ $depth -le 0 ]; then