Provide a way to refresh the build list in KojiTag

[jguiditta]

Description

Currently, we get the taggedList once and only once in kojiTag.builds method. Consider adding a way to refresh this list (perhaps with a 'force' param or similar), and decide what, if anything, to do with the **kwargs originally passed in.

[yazug]

you can work around this by setting .tagged_list = None
but that is not obvious.

if you follow down the logical path this way the workflow might be better to have builds() method always call the api but not return any data, and then force using other accessor methods to retrieve the actual data that builds(...) call gave you. But this might be more of a v2 refactor than a simple cleanup