Remove import of dummy_thread from _thread module (issue #124)

Author: edschofield

src/_thread/__init__.py

@@ -3,10 +3,7 @@
 __future_module__ = True
 
 if sys.version_info[0] < 3:
-    try:
-        from thread import *
-    except ImportError:
-        from dummy_thread import *
+    from thread import *
 else:
     raise ImportError('This package should not be accessible on Python 3. '
                       'Either you are trying to run from the python-future src folder '