Breaking changes when upgrading to plyvel v1.0.2

[metachris]

The latest plyvel release (v1.0.2) has some breaking changes it seems: https://travis-ci.org/CityOfZion/neo-python/builds/329522567

Traceback (most recent call last):
File "/home/travis/build/CityOfZion/neo-python/neo/Utils/WalletFixtureTestCase.py", line 59, in setUpClass
    super(WalletFixtureTestCase, cls).setUpClass()
File "/home/travis/build/CityOfZion/neo-python/neo/Utils/BlockchainFixtureTestCase.py", line 51, in setUpClass
    cls._blockchain = TestLevelDBBlockchain(path=cls.leveldb_testpath())
File "/home/travis/build/CityOfZion/neo-python/neo/Implementations/Blockchains/LevelDB/LevelDBBlockchain.py", line 154, in __init__
    for key, value in self._db.iterator(prefix=DBPrefix.DATA_Block):
File "plyvel/_plyvel.pyx", line 829, in plyvel._plyvel.Iterator.__next__
File "plyvel/_plyvel.pyx", line 874, in plyvel._plyvel.Iterator.real_next
File "plyvel/_plyvel.pyx", line 91, in plyvel._plyvel.raise_for_status
plyvel._plyvel.CorruptionError: b'Corruption: corrupted compressed block contents'

See also wbolster/plyvel#68