CDB-4386 Add 'visible' to torque layer options

Add 'visible' to TORQUE_ATTRS so that it is rendered by the presenter
when asking for a torque.
CDB-4386 Fix presenter tests and add them back to the regression suite
CDB-4386 Test for 'visible' attribute in vizjson
CDB-4386 Rename variables in test
Merge pull request #893 from CartoDB/CDB-4386

Cdb 4386