* Fixed file.close() typo in test_vault_editor
* Updated unicode.py to redefine basestring properly in python3 and fixed a couple missed py27 specific code.
* Realized the patch in test_data_loader was still failing cause we are passing the string 'builtins.open' and not actually using it in that file and soe instead of failing in py34 it would fail in py27.
Unfortunately, I wasn't able to fix a bug in the VaultAES in which during
the test_decrypt_1_0 and test_rekey_migration in which VaultAES wasn't successfully
writing the writing the encrypted key to out_file (BytesIO).
Added skipping vault_editor tests test_decrypt_1_0 and test_rekey_migration in python3
since I wasn't able to successfully backport VaultAES without weird bugs.
