Create lockdown test for tag cloud

The tag cloud appears to have 100% code coverage, but it turns out that
there are no assertions regarding this part of the code, it just runs
without raising any exceptions.

Run the lockdown test with `bundle exec rake test:lockdown`.

The lockdown test is an `approval` test, meaning that whatever you
previously approved is considered the correct result.

The first time you run the test there is no previously approved result,
so the test will fail.

To make it pass copy the `.lockdown/received.html` file to
`.lockdown/approved.html`. By doing this you _approve_ the current
output as being correct.

If you run `bundle exec rake test:lockdown` again, the test should pass.
ignore rbenv file
i3
get_stats_tags computation moved to model
tags_for_cloud => cloud.tags
min
divior
cut_off_3months => cutoff
sql_90days q to method
sql q to method
sql_90days & sql merged
get rid of _90_days
less vars created in the controller
calling partial twice
mem tags
got rid of compute method
polishing Up the View
fix merge