Target new helmfile repository

What's Changed

• Updated Helmfile urls to target the new repo by @mdupras in #5
• Fix for incorrect Helmfile source repo in tests by @slapointe in #6
• Target an existing release from helmfile repo by @asimmon in #7
• Fixed helmfile github release download url by @asimmon in #8

New Contributors

• @mdupras made their first contribution in #5
• @slapointe made their first contribution in #6
• @asimmon made their first contribution in #7

Full Changelog: v1.0.1...v1.0.2