geonode/exposure/util.py:

Added some custom view decorators.
geonode/exposure/views.py:

Factored out some generic view functionality into some decorators
(1 for requiring authentication, 1 for allowing only specific request
method types).
geonode/exposure/tests.py:

Added a missing test case.
geonode/exposure/tests.py:

pep8/pyflakes
geonode/exposure/tests.py:

Updated test case mock objects.
geonode/exposure/tests.py:

Added view decorator test cases.