ansible: fix 3.x dependency scanning on OS X

On OS X with case-insensitive filenames, resolving
'ansible.module_utils.facts.base.Hardware' finds
'ansible.module_utils.facts.hardware/__init__.py', because
module_finder's procedure is completely wrong for resolving child
modules. Patch over it for now since it otherwise works for Ansible.

ansible_mitogen/module_finder.py

@@ -91,18 +91,22 @@ def find(name, path=(), parent=None):
         return parent
 
     fp, modpath, (suffix, mode, kind) = tup
+    if fp:
+        fp.close()
+
     if parent and modpath == parent.path:
         # 'from timeout import timeout', where 'timeout' is a function but also
         # the name of the module being imported.
         return None
 
-    if fp:
-        fp.close()
-
     if kind == imp.PKG_DIRECTORY:
         modpath = os.path.join(modpath, '__init__.py')
+
     module = Module(head, modpath, kind, parent)
-    if tail:
+    # TODO: this code is entirely wrong on Python 3.x, but works well enough
+    # for Ansible. We need a new find_child() that only looks in the package
+    # directory, never falling back to the parent search path.
+    if tail and kind == imp.PKG_DIRECTORY:
         return find_relative(module, tail, path)
     return module