Ignore ResourceWarnings

This switches Python back to it's default behaviour. Elasticsearch creates a lot of noise with this warning switched on, hiding warnings that may be important.

runtests.py

@@ -17,10 +17,6 @@ def runtests():
     warnings.simplefilter('default', DeprecationWarning)
     warnings.simplefilter('default', PendingDeprecationWarning)
 
-    # Don't ignore ResourceWarnings (Python 3 only)
-    if sys.version_info >= (3, 0):
-        warnings.simplefilter('default', ResourceWarning)
-
     argv = sys.argv[:1] + ['test'] + sys.argv[1:]
     try:
         execute_from_command_line(argv)