Added functional tests for ValidateOrderParameters
Added a functional test for reissue

The test does the following:
    1. Create a new order
    2. Force approval of the order
    3. Do the reissue and verify the response
    4. Query the order to verify the cert status is PENDING_REISSUE

Unfortunately, forcing approval seems to take between 5 and 15
    minutes for the API to complete.
Merge pull request #16 from pglass/validateorderparams

Added functional tests for ValidateOrderParameters and Reissue