Ignore non-object package.json files, fixes #134

Previously this would hang. Node also ignores package.json files that
don't contain objects.

Author: goto-bus-stop

index.js

@@ -540,7 +540,7 @@ Deps.prototype.lookupPackage = function (file, cb) {
                 fns.forEach(function (f) { f(err, pkg) });
             }
             if (err) cb(err)
-            else if (pkg) cb(null, pkg)
+            else if (pkg && typeof pkg === 'object') cb(null, pkg)
             else {
                 self.pkgCache[pkgfile] = false;
                 next();

test/invalid_pkg.js

@@ -0,0 +1,16 @@
+var mdeps = require('../');
+var test = require('tap').test;
+var path = require('path');
+var fs = require('fs');
+
+test('invalid pkg', function (t) {
+    var d = mdeps();
+    d.on('package', function (pkg_) {
+//        console.error({pkg_});
+    });
+    d.end(path.join(__dirname, '/invalid_pkg/file.js'));
+    d.on('data', function () {});
+    d.on('end', function () {
+      t.end();
+    });
+});

test/invalid_pkg/file.js

@@ -0,0 +1 @@
+require('./')

test/invalid_pkg/index.js

@@ -0,0 +1 @@
+T.pass()

test/invalid_pkg/package.json

@@ -0,0 +1 @@
+"just a string"