Added tag 1.4 for changeset e8e07ecf2e1b
Bumped to 1.5 in preparation for next release.
keyring/tests/test_backend.py: add a tearDown() method
for deleting all created credentials
Fix ImportKiller not working with Python 3 (Fixes #102)

In Python 3, initial sys.meta_path is not empty, so custom importer modules
should be prepended, not appended.
SecretService: allow deleting items created using previous python-keyring versions

Before switch to secretstorage, python-keyring didn't set "application" attribute.
While we support searching for items without that attribute, we should also
support deleting them.
Use secretstorage.get_default_collection if it's available

That method tries to create the default collection if it doesn't exist,
instead of just raising the error. (Present in secretstorage >= 1.0)
Update changelog