set default timeout for tests to 60 seconds

greentest/testrunner.py

@@ -36,7 +36,7 @@ one will be selected if not provided.
 # - screws up warnings location, causing them to appear as originated from testrunner.py
 
 # the number of seconds each test script is allowed to run
-DEFAULT_TIMEOUT = 20
+DEFAULT_TIMEOUT = 60
 
 # the number of bytes of output that is recorded; the rest is thrown away
 OUTPUT_LIMIT = 100*1024