Uninstall old RStudio (tools) release before helm upgrade
This avoids the helm
error old users with the old USERNAME-rstudio
release names.
The Control Panel is now checking if such a legacy release exists on install/upgrade and it runs helm delete --purge
if that's the case.
Essentially the Control Panel is now running the workaround for us (see "2 releases problem" in wiki) and more users should be able to successfully upgrade to the new conda versions of RStudio.
PR: #810
2 releases problem in wiki: https://github.com/ministryofjustice/analytics-platform/wiki/Deploying-R-Studio#2-release-problem
Ticket: https://trello.com/c/llxQG72F