Fix passing get_token kwargs to get_access

get_token takes kwargs so that a different plugin implementation might
make use of them. It is not expected that token arguments would be
passed to the code that is doing the token fetching.

Change-Id: I28aa2b8070feec76f225601069c92c535334f4d4
Start using positional decorator

Apply the positional decorator to functions. It has been added as I
think best practice would dictate, though in some places it has been
added in a way that doesn't break existing tests.

Closes-Bug: #1295881
Change-Id: I4f7ddbede4cba4ab79d144ad1f9dc83ea76f204a
Merge "Start using positional decorator"
Merge "Fix passing get_token kwargs to get_access"