tests: adjust for code move in Hypothesis 2.0.0

It appears that the Settings class was renamed to settings, and because
of this, the settings module was renamed to configuration.

https://github.com/DRMacIver/hypothesis/commit/a0e663b

tests/hypothesishelpers.py

@@ -1,62 +1,69 b''
 # Helper module to use the Hypothesis tool in tests
 #
 # Copyright 2015 David R. MacIver
 #
 # For details see http://hypothesis.readthedocs.org
 
 import os
 import sys
 import traceback
 
-from hypothesis.settings import set_hypothesis_home_dir
+try:
+    # hypothesis 2.x
+    from hypothesis.configuration import set_hypothesis_home_dir
+    from hypothesis import settings
+except ImportError:
+    # hypothesis 1.x
+    from hypothesis.settings import set_hypothesis_home_dir
+    from hypothesis import Settings as settings
 import hypothesis.strategies as st
-from hypothesis import given, Settings
+from hypothesis import given
 
 # hypothesis store data regarding generate example and code
 set_hypothesis_home_dir(os.path.join(
     os.getenv('TESTTMP'), ".hypothesis"
 ))
 
 def check(*args, **kwargs):
     """decorator to make a function a hypothesis test
 
     Decorated function are run immediately (to be used doctest style)"""
     def accept(f):
         # Workaround for https://github.com/DRMacIver/hypothesis/issues/206
         # Fixed in version 1.13 (released 2015 october 29th)
         f.__module__ = '__anon__'
         try:
-            given(*args, settings=Settings(max_examples=2000), **kwargs)(f)()
+            given(*args, settings=settings(max_examples=2000), **kwargs)(f)()
         except Exception:
             traceback.print_exc(file=sys.stdout)
             sys.exit(1)
     return accept
 
 
 def roundtrips(data, decode, encode):
     """helper to tests function that must do proper encode/decode roundtripping
     """
     @given(data)
     def testroundtrips(value):
         encoded = encode(value)
         decoded = decode(encoded)
         if decoded != value:
             raise ValueError(
                 "Round trip failed: %s(%r) -> %s(%r) -> %r" % (
                     encode.__name__, value, decode.__name__, encoded,
                     decoded
                 ))
     try:
         testroundtrips()
     except Exception:
         # heredoc swallow traceback, we work around it
         traceback.print_exc(file=sys.stdout)
         raise
     print("Round trip OK")
 
 
 # strategy for generating bytestring that might be an issue for Mercurial
 bytestrings = (
     st.builds(lambda s, e: s.encode(e), st.text(), st.sampled_from([
         'utf-8', 'utf-16',
     ]))) | st.binary()