Adds pytz for timezone support
Moves test_instrument_simple into a UTIL category

It's functionality is already tested by SA
Removes test_data_product_versions

It's been deprecated since R2, no need to run
Updates test to pass
Fixes the test_add_parameter_functions
Moves the site-data product preload test into the preload category

 - Prevents the test inheritence from running the dm extended tests
   again
 - Moves the preload functions into dm_test_case
 - Assigns the site data product tests to the dm group
Fixes add_parameter test

- Updates interface so only device data products can have parameters
  added for the time being.
Merge pull request #2167 from lukecampbell/deps

Adds pytz for timezone support
Increases the sleep
Merge pull request #2168 from lukecampbell/fixes

Fixes test failures