Fix pkg.install for one-pkg install w/out version

This fixes a bug I introduced in a commit earlier today, which would
affect modules I've been working on to prepare for #3278 (yumpkg,
yumpkg5, and apt). A traditional single package install would fail
if a version was not specified.

salt/modules/pkg_resource.py

@@ -280,7 +280,7 @@ def parse_targets(name=None, pkgs=None, sources=None):
         return [x[2] for x in srcinfo], 'file'
 
     elif name and __grains__['os_family'] != 'Solaris':
-        return [name], 'repository'
+        return {name: None}, 'repository'
 
     else:
         log.error('No package sources passed to pkg.install.')