Dont fail tests if config file has sigv4 enabled

The unit tests should not be dependent on the values in your
config file.  This fixes a test failure where a test would fail
if sigv4 was enabled in the ~/.aws/config file.
Merge branch 'fix-sigv4-unittests' into develop

* fix-sigv4-unittests:
  Dont fail tests if config file has sigv4 enabled