Switch a few of the buildman methods to coroutines in order to support network calls in methods. Add a test for the ephemeral build manager.

buildman/asyncutil.py

@@ -0,0 +1,27 @@
+from functools import partial, wraps
+from trollius import get_event_loop
+
+
+class AsyncWrapper(object):
+  """ Wrapper class which will transform a syncronous library to one that can be used with
+      trollius coroutines.
+  """
+  def __init__(self, delegate, loop=None, executor=None):
+    self._loop = loop if loop is not None else get_event_loop()
+    self._delegate = delegate
+    self._executor = executor
+
+  def __getattr__(self, attrib):
+    delegate_attr = getattr(self._delegate, attrib)
+
+    if not callable(delegate_attr):
+      return delegate_attr
+
+    def wrapper(*args, **kwargs):
+      """ Wraps the delegate_attr with primitives that will transform sync calls to ones shelled
+          out to a thread pool.
+      """
+      callable_delegate_attr = partial(delegate_attr, *args, **kwargs)
+      return self._loop.run_in_executor(self._executor, callable_delegate_attr)
+
+    return wrapper