This removes release rollback/delete functionality. This functionality
was likely not being used and thus was likely not working.
This primary driver for this change is to ease introduction of Helm 3
support. Particularly to avoid having to make API changes related to
the namespacing of helm releases in Helm 3.
This also removes the swagger api documentation as it was not
maintained.
Change-Id: I7edb1c449d43690c87e5bb24726a9fcaf428c00b
8c5e5c7d24