Handle unicode module names

When the module name is given as unicode things should just work.
This can be common when using the unicode_literals __future__ import
for example.

Author: flub

apipkg.py

@@ -174,4 +174,4 @@ def __setattr__(self, name, value):
         def __delattr__(self, name):
             delattr(getmod(), name)
 
-    return AliasModule(modname)
+    return AliasModule(str(modname))

test_apipkg.py

@@ -424,6 +424,10 @@ def test_aliasmodule_aliases_an_attribute():
     assert "<AliasModule 'mymod' for 'pprint.PrettyPrinter'>" == r
     assert am.format
 
+def test_aliasmodule_unicode():
+    am = apipkg.AliasModule(py.builtin._totext("mymod"), "pprint")
+    assert am
+
 def test_aliasmodule_repr():
     am = apipkg.AliasModule("mymod", "sys")
     r = repr(am)