Flaky test test_scrypt

[AndreMiras]

The test_scrypt is passing most of the time, but sometimes it fails.
On both Travis and dev env.

test_hashlib_sha3 (tests.test_import.ModulesImportTestCase) ... ok
test_pyethapp (tests.test_import.ModulesImportTestCase) ... ok
test_pyethash (tests.test_import.ModulesImportTestCase) ... ok
test_pyethereum (tests.test_import.ModulesImportTestCase) ... ok
test_scrypt (tests.test_import.ModulesImportTestCase) ... ERROR
test_address_hex (tests.test_pywalib.PywalibTestCase) ... ok
test_get_balance (tests.test_pywalib.PywalibTestCase) ... ok
test_get_default_keystore_path (tests.test_pywalib.PywalibTestCase) ... ok
test_get_nonce (tests.test_pywalib.PywalibTestCase) ... ok
test_get_nonce_no_out_transaction (tests.test_pywalib.PywalibTestCase) ... ok
test_get_nonce_no_transaction (tests.test_pywalib.PywalibTestCase) ... ok
test_get_out_transaction_history (tests.test_pywalib.PywalibTestCase) ... ok
test_get_transaction_history (tests.test_pywalib.PywalibTestCase) ... ok
test_handle_etherscan_error (tests.test_pywalib.PywalibTestCase) ... ok
test_handle_etherscan_tx_error (tests.test_pywalib.PywalibTestCase) ... ok
test_new_account (tests.test_pywalib.PywalibTestCase) ... ok
test_transact_no_found (tests.test_pywalib.PywalibTestCase) ... ok
test_update_account_password (tests.test_pywalib.PywalibTestCase) ... ok

======================================================================
ERROR: test_s			crypt (tests.test_import.ModulesImportTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/ubuntu/workspace/PyWallet/src/tests/test_import.py", line 26, in test_scrypt
    decrypted = scrypt.decrypt(data, 'password', maxtime=0.1)
  File "/home/ubuntu/workspace/PyWallet/venv/local/lib/python2.7/site-packages/scrypt.py", line 173, in decrypt
    raise error(result)
error: decrypting file would take too long

----------------------------------------------------------------------
Ran 18 tests in 15.083s

FAILED (errors=1)