Converted existing /plans* and /plugins tests to use _call. See #2.
Added functional tests for /scan* endpoints. See #2.

A minor modification has been made to ``put_scan_control``. See
ticket #54. What remains to be done is actually testing running plugins.
Right now plugins don't start according to output. See #55.
Added /reports* api calls to the tests, but #56 prevents writing tests.

Ticket #56 is blocking me from writing actual tests. It seems like we
have to add users record to either sites or groups. But Stefan will help
me handle this as well tomorrow.
Merge pull request #57 from yeukhon/issue2

Added functional tests for almost all apis except /reports* due to bugs #52 - #56