Ignore ImportWarnings in tests.

I can't reproduce this, but apparently in some situations setuptools
throws warnings about unrelated packages, so just turn them all off.

Closes #524

diff --git a/tornado/test/runtests.py b/tornado/test/runtests.py
index 4235aba18a6ffb64df7ea4262dbe1ed4bb6ffb7e..66e90f2bdddf50c643ba584e8448bd07ef1a7214 100755 (executable)
--- a/tornado/test/runtests.py
+++ b/tornado/test/runtests.py
@@ -42,6 +42,9 @@ if __name__ == '__main__':
     # ignored by default, including DeprecationWarnings and
     # python 3.2's ResourceWarnings.
     warnings.filterwarnings("error")
+    # setuptools sometimes gives ImportWarnings about things that are on
+    # sys.path even if they're not being used.
+    warnings.filterwarnings("ignore", category=ImportWarning)
     # Tornado generally shouldn't use anything deprecated, but some of
     # our dependencies do (last match wins).
     warnings.filterwarnings("ignore", category=DeprecationWarning)